There's some interesting post election anaylsis that picks up on this (in Wales at least). There's a view [0][1] that while results are bad for Plaid, they're getting a lot of what they want, and shifting the window on the most important issue (independence). In addition to UBI, it's interesting that Welsh Labour have started the push for "home rule" [2], something that is likely to win them a lot more votes from traditional Plaid Cymru supporters.

[0] - https://nation.cymru/opinion/this-was-a-bad-election-for-pla...

[1] - https://www.thenational.wales/news/19303406.plaid-cymru-noth...

[3] - https://www.walesonline.co.uk/news/politics/mark-drakeford-d...