The simple answer is "yes".... those two L-series lenses would give you noticeably sharper, less distorted, more richly colored images with less chromatic aberration.
However, those lenses are also big, heavy and expensive.
It IS NOT the f/2.8 aperture which makes those lenses "better" in the above ways. f/2.8 gives you potential for stronger background blur effects and the ability to shoot and stop action in lower light conditions.
You might want to instead consider the Canon EF 24-70mm f/4L IS USM and EF 70-200mm f/4L IS USM II (or the original). These are also extremely capable, high quality L-series lenses that are about 1/3 smaller and lighter than the f/2.8 versions, plus are about 1/3 lower cost. Also, the f/4 version of the 24-70mm has Image Stabilization... the f/2.8 version doesn't (it helps steady shots at slower shutter speeds, but IS can't help freeze subject movement, you still need a faster shutter speed for that). Also, the EF 24-70mm f/4L is
amazingly close focusing. It's able to do .70X magnification on it's own, nearly 3/4 life size. That's 2X to 3X higher magnification than the f/2.8 lenses can do.
Another alternative you should consider if you really want an f/2.8 zoom in your camera bag, get the Canon EF-S 17-55mm f/2.8 IS USM instead. It's not as close focusing as the 24-70mm f/4, but it has what some people consider a "better" range of focal lengths for a crop sensor camera such as the 77D. It's not an L-series (by definition, no EF-S lens can be), but it's got image quality the equal of or better than many L-series. And it's got
both f/2.8
and Image Stabilization.
I have an older version of both 24-70mm f/2.8 and 70-200mm f/2.8. I use the 70-200mm so much I got a 70-200mm f/4L IS USM as a "backup". But I find I actually use the f/4 lens more often now, since it's so much lighter and more compact, yet has equally good image quality in all respects except for it's ability to blur down backgrounds.
Still, even and f/4 lens can render pretty strong background blur and shallow depth of field effects when used close to subjects:
70-200mm f/4...
I haven't got the 24-70mm f/4... yet. But probably will when I get my next full frame camera.
By the way... if looking for even stronger background blur and shallow depth of field effects, prime lenses (rather than zooms) can be a better way to achieve that. For one, primes can have one to two stops larger aperture than an f/2.8 zoom, yet still be quite reasonably sized and affordable, compared to the "fast" zoom. For example, the Canon EF 50mm f/1.4 USM or EF 85mm f/1.8 lenses are far smaller, lighter and have potential for much stronger background blur than a 24-70/2.8 or 70-200/2.8 zoom. The Canon 28mm f/1.8 USM, 100mm f/2 and 135mm f/2L are no slouches, either.
The simple answer is "yes".... those two... (