You can also have wikis or defederated platform, you should know, you're on one...

Internet is the definition of a decentralised information sharing system, though. If you don't like your current search engine, you swap to another. If you can't find the information you need on one forum, you go to another. If you have the information more accurate and up to date than the list you find online, you update it (if it's in a wiki format) or contact its author to contribute.

Centralisation of the internet is the direct result of authorities trying to impose their will on people who didn't consent to it.

We're on the fediverse, if you don't like one server you go to another. Maybe you moved here from reddit? Systems can be created with anarchism in mind.

If the list is such an important resource that managing would give the person / people too much power, mechanism to mitigate that could be implemented either from the organizational side or from the technical.

Examples for organizational mitigations could be:

• management of the list rotates between members of the community
• the power to make decisions and the role of management could be split: the community decides on a policy, the people responsible only implement the policy

Technical mitigations might be:

• design the list to be decentralized, like the fediverse where multiple list exists, they get federated and noone can monopolize the knowledge
• list are maintaned similar to code repositories where everyone can make a copy, change it, fix it etc.

Also like... why would you do that in a world where nobody else does that? Growing up / living in a society where sharing, solidarity, equal access to ressources etc. are the norm, its hard to imagine this being much of an issue. There wouldnt be a profit motive, being in a position of power would be undesirable and maybe even looked down upon and you could spend your effort for something actually fullfilling. But even if that issue would pop up, a society attuned to a anti authoritarian life style would be easily challenging that situation anyway. When capitalism, the state, and hopefully other systems of power are out of the way, this small problem would probably get dealt with in a single meeting or mediation session. Because its so miniscule in the grand scheme of things.

I admire the ideals of renaissance men trying to become proficient in every possible skill ...

Look, maybe given the situation you would try to become proficient "in every possible skill", most people will just focus on a few key ones, and maybe have a few auxiliary ones.

No one is telling you to put your life in the hand of a hobbyist, but if you had a big wooden table with a broken leg, would you rather buy a new table (seeing as actually finding someone who deals with woodwork in this economy is almost impossible), or go see a friend/neighbor/friend-of-friend who does woodwork as (mostly) a hobby, and trade favors with them in exchange for keeping your old table you are probably sentiment about for longer than expected?