Just look at Rateyourmusic rating of britpop. Everything Must Go
It considered the 4th best Britpop album of all time and rated higher than Blur's Parklife which to me seems absurd but the public has spoken
I believe you are fan of Blur and Oasis (I think Pulp as well). So if you want to learn about the britpop era and learn what was popular during this era then you should listen to at least Everything Must Go. If you like that then perhaps the two albums afterwards.
Back in the old days when I used to listen to the radio and watch music video shows like rage/video hits (Australian version of MTV). Manic Street Preachers were very very popular and had a lot of radio play. Won brit-awards etc. Whether the music is good or bad or whether those albums are within your taste or not, they were significant albums. At least Everything Must Go is considered a seminal brit pop album winning the britaward of album of the year. The album charted number 2 in the UK the follow up was number 1 charted.
Although I am not familiar with their albums (i may have listened to Everything Must Go, This Is My Truth Tell Me Yours and Know Your Enemy once 20+ years ago as my brother was a fan but I can't remember the album which doesn't bode well to the album quality) but I do remember the singles. I think I may well agree of Tabernacles assessment of generic mainstream rock but at least it is historically significant generic mainstream rock within the subgenre of britpop.