This is good game design. Dynamism is what makes a great open world, you need a lot of it, that changes OVER TIME, some rng to it, with a system that recycles itself. If you can finish all the open world activities in 2 weeks and get all the rewards you designed a bad open world system. If it takes you 6 months to a year, you designed a great system. If you designed it as a "decaying" system you reached "god mode."
Calm down there, Skinner, youve been dead 30 years, game design ideas based on your nonsense are just taking a little longer to catch up.