They can only resist this for as long as the offers are below their expectations, but trust me, if someone brings in some big money, they will sell.
Following PSG's success, I think in the next few years, there is going to be an inflow of oil money into other potentially big clubs. We saw the same thing play out in the English Premier League. Remember when Roman bought Chelsea? Rich folks started getting interested in other top clubs in the league, and the rest is history.
These are clubs that have been around for many years; the members, the directors, they all treat the club as a long-term business with very high profits that they don't even declare, so they're not going to sell their gold mine. When it comes to clubs in the third division, fourth division, or in some cases the second division, and that haven't been profitable, then these clubs are easier to sell. Now, in the case of first division clubs, especially in leagues like Ligue 1, the directors are unlikely to sell. It's true that there are cases like Chelsea, Manchester United, and many other first division clubs that have been sold, but these are few and far between.