The number of compound types (four) is fine. However, instead of allowing strategies ranging from 2-stop to 4-stop, these tyre compounds should allow no-stop to 2-stop strategies. (ie. make the tyres less prone to degradation, then drivers are allowed to push the cars more aggressively.)
Bring back Quali tyres, allow them only in P3 and Qualifying. Limit the number of Quali tyres available in each qualifying session.
Scrap the front 10 tyre rule and the ‘compulsory stop’ rule.
Allow different tyre compounds fitted to different wheels during race. Then we can see conservative approaches where harder compounds are fitted to outer wheels and softer compounds to inner wheels.