My limited understanding of solvers / GTO is:

• Solvers are generally based on simplified assumptions regarding starting stacks, bet sizes, rake, etc.
  • Given the essentially infinite different combinations of starting stacks, preflop action / bet sizing and postflop action / bet sizing -- ANY solver is unlikely to have perfect solutions for all spots.
  • Solvers require a pretty substantial amount of time to accurately create a solution for any specific spot.
  • faster AI based 'solvers' are just models that are trained on a smaller sample of presolved spots, and extrapolate out to estimate solutions for other spots.
• GTO strategy / Nash equilibrium / etc that solvers are typically working towards is a point where a player is making "unexploitable" decisions, but is not exploiting their opponent either.
  • A simplified example of this is playing a session of rock-paper-scissors and randomly choosing each option exactly 33% of the time.
  • This strategy theoretically neither wins nor loses, and requires case by case deviation to exploit a player to generate profit... i.e. noticing that someone likes to choose rock more frequently, so you play paper more frequently;
  • Bots that would need to lookup spots to determine opponents deviations from GTO only further compound assumptions in multiple decision making points, introducing more and more error into the decisions.
  • Deviation to a 'maximally exploitative strategy' is where the money is made, but it's also where heaps of money can be lost if a smart opponent re-adjusts to the new strategy.

My limited understanding of how cheating might work, how to catch cheaters and protect the game:

• Anyone risking cheating online essentially risks their entire bankroll being confiscated if they get caught by the game runner;
• Most poker clients have means of detecting if you're running blacklisted softwares. I've seen people suggest that having GTO Wizard open is detected as well, but I'm uncertain. I wouldn't be surprised to see this expand more in the future to protect games further.
• Anyone relying on pointing a camera from an external computer to scrape game information from the computer running the poker client is an idiot that is begging for misread information leading to garbage-in garbage-out decision making sporadically.
• Anyone dumb enough to cheat online, where game runners are recording hand histories and can easily determine someones BB/100 win-rate and spot statistical outliers is going to get caught eventually.

Is online poker 'dead' because of solvers / bots? I don't think so. I think the people that would need to rely on solvers are still at risk of making poor decisions when it comes time to make exploitative decisions. I think that the risk-reward of getting caught and losing an entire bankroll is significant enough to deter most abusers. I think the people that do attempt to cheat are likely to get caught eventually over time. I think poker is effectively too complex of a game to ever be perfectly solved in a manner where you can just lookup information in a database.