He wasn't "jumping" you, he was asking some very relevant questions. Part of reason people join forums like this is to share ideas and knowledge.

Just an analogy, in the automotive "hot rod" world, a maxim is there's no substitute for cubic inches, so in photography there's no substitute for good glass. In other words more zoom reach will trump higher pixel count. Sure you can turbocharge that smaller engine.. or max out pixel count.. but there's always a downside. Ken Rockwell has an interesting article on pixel dumping.. can you really use 61MP?
https://www.kenrockwell.com/tech/pixel-dumping.htm
Of course in 10 years we'll laugh at that too, and we're always pushing technical limitations, just because we can.
I'd say cost is probably a consideration in getting a new camera, but then that depends on the size of your purse. Perhaps you've got an oil well in your backyard and want the latest and greatest.

Well if you're not interested in industry trends, fine, but don't complain when someone who is interested reports on topics like this.

I agree with most of the posts here, if you want "perfect", at least cosmetically, buy new. I bought a minivan that had been in a wreck, rebuilt, and dumped at an auction. I paid about $2000 less than what a pristine example of the same mileage would cost. It's got a bumper that slightly misaligned and some of the paint doesn't match exactly, but it's been 100% reliable in 18 months. Yes, I will also get less for it when I sell it, but I financed less money to pay for it. Basically used is always going to have some issues. Also new products can have issues, there's obviously quality parameters for production or you would never make any money and go out of business. Also @Thomas902 has a good point about refurbished cameras, these are warranty replacements, fixed mechanically and put into a new shell, new screen, so it looks like new, and you save some money. Of course there is usually only a short warranty to you, but the warranty eventually runs out on everything, and there might be a smaller chance something else would break. You either want a "trophy" piece of gear sitting pristinely on the shelf, or use it, dings and all. YMMV. Caveat Emptor. Void where prohibited by law. Tag may only be removed by purchaser. You pay your money and take your chances, as it were. Life is short, enjoy the ride, and take nice pictures along the way.

As an IT Tech, you have to ask some basic questions to troubleshoot. If it was a computer issue there is tons of info out there on reasons for a computer slowing down, hard drive failing, RAM maxed out causing memory paging is perhaps the most common for older computers, malware, etc., fixes may be upgrade hardware, reinstall OS, new hard drive, etc. In this case I'm assuming the computer/operating system is not slowing down, just Light Room. Optimize the catalog first. Backup the catalog, reinstall Light Room. If that doesn't fix it, and the hard drive is not close to full, perhaps reinstall Windows on a SSD drive - this is a quick and inexpensive fix for older computers. You can keep the old drive for photos. Failing all that, perhaps it's time for a new computer.

This is the most correct answer. Windows tends to get stuff added to it which requires more resources (CPU, RAM) and sometimes uninstalling programs does not remove everything. There could be a poorly written program, or most worrisome, undetected malware. Most likely some driver or function is hanging, eventually "timing out". Backup your data, upgrade the RAM to 16GB, install an SSD (solid state drive), and reinstall Windows on the SSD.

The latest NanoUSM version of the 18-135mm EF-S is an excellent general purpose lens for APC Canon cameras, I use it on my 80D. I also have the 10-18mm EF-S, another outstanding lens, when I need a wide angle. Between these two you really don't need anything else for most things. Ken Rockwell has good reviews on both of these lenses http://kenrockwell.com

Sure, new equipment is sexy, if I only had x camera or y lens..!! Caveat emptor, new or improved camera technology may make taking pictures easier, or faster, or be a little more accurate, but if you can't take good pictures with your current camera, new technology isn't going to help.

If you are going mirrorless, you have to go buy the native lenses for that platform. Sure you can use adapters to fit other lenses, like Canon EF lenses on a Canon RF mount, but the mirrorless cameras are really a clean sheet design and the native lenses are designed to work best with that camera. So the question is how much better/smaller/lighter is it, and is it worth selling you current gear and paying ridiculous prices for a new mirrorless system like Nikon Z6, Z7, Canon R5, R6, Sony A7IV + all new lenses? Actually if weight is the main criterion, you need to figure the weight of the camera and lens together, you might find the mirrorless alternative doesn't save much weight after all. Maybe Micro 4/3 is good enough, just get a tele for your Olympus OM-D and you're done.
Simplify, really who has time to change lenses. Pick one and go with it. If your zoom is not long enough, walk forward until it is. Sometimes you can't do that of course, only you can determine what works best for you. Ken Rockwell has some good insight about photography on his website, which I'm not going to link to here, but you can easily find it.