very few groups have waiting lists at the moment, since Covid there’s less children coming through Scouting and taking a while to recover. Groups are also encouraged to not keep a waiting list and share spaces around with other local groups
While there are bound to be local variations, it's not true to say that very few groups have waiting lists, and scouts is taking a while to recover. As a whole, since Covid, scouts has experienced a massive uptake of young people, and at one point had 90000 potential members nationally on its waiting lists.
We currently have around 30 children waiting to join beavers, we already have 2 beaver colonies, and could do with opening another one, or even two, but it's the usual story of too many children wanting to do it, and not enough volunteer adults to be able to make it happen.
Having experienced both Rainbows and Beavers (though the eyes of my DD) I would say that, on the whole, beavers was better for her. I fully accept this is at least partly due to leaders, but I also think having a mixed group pushed my DD to try things she might not otherwise have done.
Of course, I am slightly biased, as I am a cub leader, but I wasn't when my kids were younger. I could just as easily have volunteered at Rainbows, but I just felt that the things that scouting offered fitted better with what I wanted to do.