I first started playing Violet a month and a half ago. A couple weeks into playing my wife expressed interest in playing too. So I got a copy of Scarlet for her. Since I was so far ahead of her (both in the actual game and knowledge of the games, I have been playing since LG/FR, while she has only played GO) I decided to take a break from Violet to finally play Shield. I purchased it when it came out but never left the starting town.
I have now beaten Shield and use the raids there to level my Pokémon in Violet. In Violet I have beaten all of the gyms, all of the Titans, and just have 1 more Star Base. When trying to join a Tera raid I can only join random ones, the ones on be board always say I failed to join. But doing the random raids I end up with so many 1*-3*s. When I am looking for raids I am having the same issue, they are all lower.
Even before I became the champion in Shield it was faster to level by transferring my Pokémon.
Lower level raids still drop lower tier candies. Mid game grind shouldn’t be too bad when doing the overworld auto-battles, I don’t remember what those are called.