I don't think we can completely out rule using the money gained from player sales to purchase new players that aren't out of contract or only available on loan. We bought Onana for over 30 million pound on the back of selling Richarlison just a couple of years ago, for example. The sales of Brantwaite and Onana are going to bring in a similar amount of money that clubs get for winning the Champions League, so nobody is going to be shocked if Everton sign a couple of new players on the back of our humungous profits from players sales.
Having said that, we do occasionally have summers where we really are skint and we are only limited to loans and free transfers. Like the Benitez summer transfer window, and when we went several years without signing a first team player at one point under Kenwright, which was the period when the Arteta money went straight to the bank. But for the most part, we have re-invested profits derived from player sales on signing new players.
Loan signings and free transfers are often better than 30 million pound big money signings anyway. Ross Barkley on a free would likely be a much better signing than the 40m+ spent on the likes of Klassen and Gomes etc. It's entirely possible that the likes of Che Adams and Chris Wood signed on a free would provide a greater goal return than 25 million pound Beto.