Of course, whatever functions longer has more credibility: PoW ~6 years, PoS -1 year, PoI - 0 (still in testing). However, dismissing flaws and vulnerabilities in systems that have run for a long enough time is not constructive. "Good enough" may be not enough for some rare case situations, which can happen under certain conditions, those rare case situations should be foreseen and measures should be applied prior to such events, it's only common sense in engineering.
Precisely. Its always good to look at ways to innovate rather than stagnate. PoW has flaws, that can be accepted or a better alternative may be searched for.
PoS itself has evolved from the basic to TF, DPOS, PoI. It will continue to improve so rather than dismissing it as it may represent a threat to some groups, it should be welcomed.