I don't know if it's true or just fiction but at least, if Messi leaves PSG and chooses to play for against Ronaldo again then it looks like the competition there will also be more interesting. So, if you also believe Benzema to accept the offer, then I think Messi also can accept the offer. Because after all, I think Messi is also not suitable at PSG and moreover Neymar has also been widely rumored to be leaving for the Premier League.
If I were any of these players, I would accept such an offer. It looks like the last chance to earn a lot of money and on the condition that in the near future you will not be very disappointed. If you look at the trend, over the past 10 (and if you take 20, even more so) years, the salaries of football players have increased many times over. If the trend continues (and inflation plays an important role here), then in 5-10 years some average near-top footballer will receive for one contract (3-5 years) as much as at the moment the legendary footballers have earned in their entire careers. Therefore, it is better to hit the jackpot now and for a long time not to think about the fact that young people overtake you in terms of income.