I don’t see how what conservatives say has to do with reality.
Biden has been “senile” and “too old” for years now, during which time we’ve had a functioning Biden administration.
The Trump admin was limp, chronically understaffed, weak, ineffectual. That’s what they’re pretending is better than Biden. Conservatives don’t even care about senility so if you hear them rag on Biden and think they’re right, you’re not understanding what they’re really saying.