Yea, they can live pretty long. It’s mostly the dangers out there (cars, people, poison, other animals) that shorten the lifespan drastically.
That’s why indoor cats have a longer lifespan on average.
Also, the kidneys… keep an eye on them and your cat should do pretty well for a long time
Just a wild guess: are you using the 5ghz or 2.4ghz Wifi? 5ghz is way faster but very fidgety with larger distance to the router, walls in the way or other routers nearby.
So, maybe you can troubleshoot your way out:
Good luck!