>>1042589this on several levels.
i have a canon body and there are times that i eye other bodies (like the fuji x-t2) because it just looks so much more practical in recreational settings (basically when i travel to conferences and want to go out and about and taking pictures like a tourist), but i've saved a stupid amount of money buying really high-end lenses used off of craigslist, and even if i sold all of my pro gear now (i used to shoot a number of types of events professionally to make some extra money, but i don't now), i would probably only *barely* scrounge up enough for the body and lenses i would want for the landscape and travel photography i do as a hobby now.
tl;dr canon certainly has drawbacks, but the deep deep selection of quality lenses and accessories ultimately makes up for it. Nikon is the next runner up with enough lenses to say they're in the same ballpark as Canon, but the older lenses that put them in the same ballpark as Canon lack things like autofocus. if you restrict it to lens selection with all the modern features you'd expect to see (i.e. AF), then the lens selection drops precipitously. that being said, you could probably still find lots of cheap used lenses on the canon side.
some other systems (like pentax? i think?) offer bodies that have image stabilization built into the body. this means that every single lens you use gets the added win of image stabilization, which isn't a trivial thing. it irks me to no end that canon and nikon don't implement something like this, but in my case it's still not enough to drop everything and switch systems. if you think IS is something you'd really like, and if you don't mind having an anemic selection of used lenses to buy cheap, then look into that.
and yes, you should almost certainly buy lenses used when available. most lenses worth carrying around on a photoshoot are built so ruggedly that they should last decades. unless the previous owner has seriously abused it.
