Lounge access is something I've got used to from many years of long-haul business travel, hence my SEN status of almost 20 years. Unfortunately I didn't reach the necessary million miles in a ten-year period, so missed out on SEN for life.
Since most of my flying these days is within Europe for the cheapest fares, mainly on SN but also on other LH group members and LO, the lounge I use most is BRU which is preferable to the zoo outside, especially now that it has been extended.
Lounge access in Spain is also good to have, as the airports there are usually very crowded.

Snow delayed my LH return from MUC last night by over two hours so I was glad I could go to the (almost empty) SEN lounge, and there was even a lot more than just potato salad.

As a SEN I have never had any trouble getting mileage tickets for when I wanted and then there are partner tickets for half the number of miles.
An added benefit here in Belgium is free Amex (and for partner) and Mastercard. although the miles earning rate on the latter was 'enhanced' last year.

But I would agree with previous posters on another thread that it really is down to individual choice.

For the future, if the absorption of SN into Eurowings means that EW rules apply and cheap tickets on SN lose lounge access, then I shall have to reconsider.