This is an incredibly limited understanding of what "politics" entails and also seems to be primarily informed by the outcome of the US political system.

Most politicians outside the narrow world of US national (or otherwise high-profile) politics have very little contact with fundraising or advertising and few will ever give a speech to more than a handful of people. I.e. most parliamentarian democracies are chuck full of politicians that even most of their direct constituents couldn't name with a gun to their heads, even at the national level.

In these kind of systems, actual expertise is really important and political parties will cultivate subject-matter experts and provide them with secure seats or list positions without necessarily putting them into front-row politics. It's just the smart thing to do, if you actually want to have any effect after winning an election.