I am a solo indie game dev - and have released Industry Idle[1] - a factory building/supply chain management/trading sim about two years ago during pandemic where I've got some free time. Now I am working on a spiritual successor called CivIdle while maintaining Industry Idle (it has a global real-time player driven market, which surprisingly takes quite some effort for maintenance, and that has slowed down the new development by a considerable amount)
P.S. Industry Idle has been open sourced a while ago, if anyone is interested in the code[3]