You don't own the games so when Nintendo release their new console and shut down their old online service to start their new online service, say good bye to your games.
X360 came out in 2005, PS3 and Wii in 2006, only 1 of those services have been shut down. You can still buy games on PS3 and X360.
Nintendo have done absolutely nothing to convince me that their next consoles online service will be the same as Switch's.
So yes, paying $20 a year or whatever it costs is taking it in the arse right now.
*EDIT*
And besides that, they already had online play on Switch when the console released. You are giving them money for something they can provide for free.
eh