I think a lot of people are hoping for a Sims 5 with the hope that it will be done as a Sims 3 reboot but I highly doubt that would be the case. If there was to be a Sims 5 at some point down the road, my thought is that it would just be Sims 4 with a few extra functions and a lot of negative changes, like Sims 4 was when it was released.
As far as fixing the many problems Sims 4 has, a lot of it was by design so we're stuck with it like the districts with the tsunami of loading screens instead of the open world concept. If they do decide on a Sims 5 at some point, the best idea would be to not do even the tiniest scrap of programming on it without polling the fan base, get the player's perspective, and making it based on what we the customer want, not what sounds good on paper, after all, anything can sound great on paper, in reality, ehhh, not so much.
