I totally agree with you about this.
Messi was already ready to take a 50% pay cut to sign for Barcelona again while he was a free agent. But even then Barcelona weren't able to afford his contract due to big financial issues. If they were as strong as now financially then I'm 100% sure that Barcelona would sign him without thinking about it twice. Therefore it wouldn't be fair to go harsh on Messi about this topic. He still loves his old team very much and I'm pretty sure that he is ready to take advantage of any chance he might get in the future.
Barcelona financial nowadays seems better than Lionel Messi contract over and I think he has chance return and retired with Barcelona looking his contract almost ended left one years until 2023 on PSG. I sure with healthy financial right now not problem for Barcelona get back Lionel Messi but waiting become free transfer player need one years later until Lionel Messi contract over with PSG in 2023. Not running well because PSG have rumor will extended and give offering one years later contract for Lionel Messi and he will receive the same amount of his salary and not any cut off.
Barcelona have chance to sign in back Lionel Messi if can pay higher salary received from PSG and I don't think become problem for next years after Barcelona have good financial, now depending with Lionel Messi will return to Barcelona or keep extended with PSG and have another option by joining with other league maybe Primer League or move to MLS.