I was thinking about the main attraction of the M system for me, which is the compact size/weight it offers, so that it can be used as a very light setup on its own and/or as a second body for the EF system to take on an adapted EF telephoto lens for wildlife; or simply as a backup camera/lens to an RF system. In these scenarios, the light weight & small size make carrying the M system around much more attractive. And with a 32MP M5 Mark II, the IQ would at least be very good if the M lenses can match up.If you mean to get the most out of it then yes that is true.
If you mean for it to sell then as long as it is priced right it will sell.
Serious photographers can adapt EF lenses.