In isolation, maybe, devoid of some other rules. We ultimately got the engine-layout-by-committee that no one wanted; six cylinders as a chassis brace and a marketing hedge against having two cylinders fewer. Consider that every motorsport is fuel flow limited to some degree by nature of combustion properties and fuel cell weight. This inherent limit was deemed not good enough by F1, and its larger culture, that wanted there to be some sort of connection to road cars which I think was a way to justify budgets. Which is to say, F1 became too reliant upon advertising money, specifically manufacturer involvement. RB and McLaren and Williams could run a better version of F1. RB trying to get into the engine biz is interesting in this sense. Said another way: if a Cosworth can't supply an F1 engine, is it still F1?
Technology could permit the simplification of engine development if only the regs would allow it. The non-works teams should be manufacturing engines on their own.
F1 was a niche and should become one again. Automotive mega corporations should perhaps be shown the door. That or the non-works teams should conspire to form a counter series. Way things are going, the works teams and their corporate donors will only be able to produce heavier more convoluted cars; electrification is where their motherships are headed, again for arbitrary reasoning. The alternative is to return to the earlier spirit of F1 which was less concerned about road relevance.
The secret may be in writing rules about who can participate. Non-works teams and, if possible, the FIA should walk away and say no involvement by corporations over a certain size (measured by employee count or profit). The cars are then composed not so diffently from how they are now; mostly in-house, with a large percentage of components from boutique suppliers. Include the engine in that mix. Engines by Cosworth, nascent RBPT, possibly McLaren.
If you ask, "How will they afford it," well, then you have to also ask, how did they ever afford it? In the history of F1. How many ads were trackside when Coventry Climax engines were running the courses? How many stickers were on the car? How large were the stickers? How does a person afford a hobby? How does a group of people afford a hobby? How does a large group of people afford a hobby?
Side question-- Do RB, Sauber and Williams count as garagistas or is there another term for them?