It's called "formula" for a reason, mate.
While the late American automotive scribe Brock Yates used to call for Formula One to just dump the rulebook and allow teams to "run what you brung" with unlimited flexibility, that defeats the purpose of a formula.
I do miss the 1980s and 1990s when you had a mix of V8s, V10s and V12s in the field, but as you note, eventually one configuration becomes "the best" (in this case, V10s) and everyone moved to it. So whether or not you define certain technical aspects in the rules, the teams will eventually find "the best" because that is one of the things that makes Formula One what it is.
While the late American automotive scribe Brock Yates used to call for Formula One to just dump the rulebook and allow teams to "run what you brung" with unlimited flexibility, that defeats the purpose of a formula.
I do miss the 1980s and 1990s when you had a mix of V8s, V10s and V12s in the field, but as you note, eventually one configuration becomes "the best" (in this case, V10s) and everyone moved to it. So whether or not you define certain technical aspects in the rules, the teams will eventually find "the best" because that is one of the things that makes Formula One what it is.