Main reason to run a node is to keep the network decentralized.

For the first 20 years that is to ensure a relatively fair emission -- which 99.9% of other coins dont have.  This makes bitcoin open rather than proprietary.

The second reason is to keep the network secure.  Dev in bitcoin is very good, but it is not bullet-proof and had to be fought for.  There have been multiple civil wars already, won by the users.  The power of a UASF can be used for good or for bad.  I believe alby users will be a force for good, because bumi has always defended users and bitcoin.

We will face another group that tries to for bitcoin.  Either a soft fork (OP_CODEs) a hostile miner fork (drivechainers) or a hard fork.  Some forks are good (e.g. consensus cleanup), some are bad (e.g. drivechains).  All forks are bad because they risk a chain split.  And a chain split could be terminal to both splits, and damage investors that put their trust in bitcoin.  We will need to fight and win 1-2 more battles like this before bitcoin becomes a long-term asset, which I think everyone wants.  Alby hub and its culture may be what tips the balance.

The other stuff including lightning is a "nice to have", but more for hobbyists right now.  Glad it's getting easier over time, tho. 

 >Main reason to run a node is to keep the network decentralized.

No... the main reason to run a node is to validate your own transactions privately. 

Plebs of little to no economic relevance have practically no impact on the outcome of forks or Bitcoin's "decentralization".

Run a node for your own benefit, or don't, but let's not pretend doing so is an altruistic act.  

 UASF also acts as a powerful signal.  It was critical in the past. 

 UASF worked because economically significant actors rallied behind it. 

The larp of every user running a node just for the sake of defending the network is just that... a larp 

 I agree so much with this.  There is alot of LARP.  But nevertheless users and UASF offer a counter balance to those trying to fork bitcoin, another layer to the game theory.  Would you not agree with this.   

 Wait a second.  The economically significant actors backed segwit2x. 

 No they didn't. VC-backed companies are not the economically significant actors within the Bitcoin community. 

Actual skin in the game Bitcoin holders wanted nothing to do with the fork, as evidenced, for example, by Finex's futures market at the time.  

 It's a good point and we've probably covered enough for one day, because I'd like to keep the discussion going and for it not to turn adversarial.  But the miners were significant actors, too.  Both VC backed and Chinese.  Had they teamed with roger they would have got the longest chain, with slush pool mining the minority chain with about 5% hash.  That would have lead to a 1/4 ing of the hash.  And the other chain races ahead, btc becomes a chew tow for the miners with famine and feast or chain death.  Dont get me wrong the futures market played a big role.  Though it was not even fully understood at first.  But there were multiple prongs to the defense strategy.  Ends. 

 Bitcoin is the longest *valid* chain as determined by economic consensus.

What miners decide to do is irrelevant 😉  

 To be continued ... ;)