I skimmed (i.e. listened to fairly long sections of) each of the songs on the playlist. It's a highly well-curated list of 21st century independent music. My own background skews toward 20th century, but surprisingly my favorite tracks were the least Beach Boysish (the Dane Terry song was an amazingly close tribute, but it didn't do much for me other than that).

Most of my 21st century listening has been to Scandinavian musicians. Here are a few that come close to Beachiness.

Linnea Olsson, Summer II: https://youtu.be/tu6OZ_wqEsg

Mew, Beach: https://youtu.be/xXzRdxgaBNs

Loney Dear, Ignorant Boy Beautiful Girl https://youtu.be/K1B8KwgtkOE

Not a tribute but a reference (and an an ironic comment on the poverty and smugness of 21st century culture): Hello Saferide, I Was Definitely Made for These Times, https://youtu.be/RiuIorq1I4I