You should be sceptical imo and that's probably a good stance to take with any new prospective owner.
The truth is we don't really know what will happen. But I think the competition in the EPL will dictate how a prospective new owner will run the club. The EPL right now is the most competitive league in the world and it would be naive for any new owner to impose their own will on the football side of the club.
The best run clubs in the world are those clubs who allow their football departments to make the decisions on the football side of the club. And a good owner is one who will then empower those people and expect results. Because when you expect high standards as a owner, then you will create a culture at the club where people will be held accountable for their roles on the football side of the club. The last 10 years under the Glazers, Ed Woodward was bulletproof after making countless mistakes. And it was reported that the Glazers tried talking Woodward out of resigning from him role after the Super League debacle. And you aren't going to create high standards when the owners care more about keeping their favourite employee around, rather than wanting their club to challenge for the highest honours.
But if we look at both PSG and Nice currently, they're both being run well imo. Nice have had ups and downs where mistakes were made. But right now it seems like they have a young up and coming DoF in place and he seems to be doing okay at the moment. And PSG have also put in place Luis Campos, who is well known when it comes to recruitment and he along with Galtier are running the football side of the club. Campos' recruitment hasn't been great but PSG have allowed him the freedom to make the big calls when it comes to recruitment and appointing a new manager.
One thing I'm confident about, is that whether it's Qatar or INEOS, we will have much better owners than the Glazers. And then it's about empowering the people working on the football side of the club. And it's not about how quick players can be signed in a transfer window but rather if those players fit a playstyle that is being developed.