If not then we have only one other choice: drastic reduction on aero performance, strict regulations curbing all aero development. If your performance is not coming from aeo, you can follow another car; if it is all about aero = DRS is necessary. Don't forget, this is not a new invention, push-to-pass has been in open wheel racing for decades, in the 80s it was literal turbo boost..
So we either have 340km/ top speeds or 280km/h with even more reduction to average lap speeds due to aero parts that could be stamped in 1971.
I've been saying this for years. What's wrong with reducing downforce until dirty air ceases to cause problems for the following car? You then have the possibillity of a quicker driver overtaking a slower one, on track, by virtue of better driving/engine/chassis/stategy or a combination of some/all of the above. People might actually find F1 entertaining for a change. Or would that be too much to ask?