It is perhaps rare for groups to survive a long time with the same line-up, but there are a good number of groups that have kept going for a long time with various changes of personnel, going under the same band name. And some their members are in more than one group, so are almost acting as session musicians for some of their commitments.
Among the solo artists are some who have always played solo or perhaps with a single accompanist, while others split their time between playing solo or in groups. There does seem to be a trend for younger emerging artists to feel obliged to form the “Joe Bloggs Band” - suggesting that it’s really “Joe Bloggs + backing musicians” rather than other groups where most of the band members get a chance, in turn, to take centre stage.
And if you are putting together a festival concert programme, it is sort of expected that you will have a mix of acts, soloists and bands, older and younger, male and female, and often, but not always, the biggest and loudest band rounding off the final act. (The exception being when you have a big name soloist,)