Drupal 8 has reached end-of-life already and is no longer supported. Drupal 7 has a year to go but there are benefits from upgrading early. Complex sites can take a long time to upgrade from 7 to 9 so putting it off to the last minute is not a good idea. Also, Drupal 9 is more performant, and much easier to work with than 7 (especially the config import/export feature which is great for deployment workflows).
We’ve got experience upgrading both 7-9 and 8-9 so if you have sites you want upgrading, send 'em over. Reasonable prices, in the low hundreds for simple sites, obviously more if there’s a lot of custom code or functionality that depends on obsolete modules. But we’ll work with you and/or your client to ascertain exactly what is needed for the particular site and take it from there.
If you are interested then reply to this message or email email@example.com