Welcome back!
HPI went bankrupt around 2016, they were chopped up and sold off to where HPI and Hot Bodies are nothing like they once were.
Hobbico also went bankrupt shortly after with Team Durango and dozens of other small brands going away as well... Hobbico was chopped up and most of their car market was sold to Horizon, namely ARRMA.
HongNor retired which left OFNA without a major brand to distribute after HoBao decided to take on their own distribution in North America so OFNA went out of business. Some of the HongNor cars have been brought back under RedCat, but not in kit form, you can still get 80% kits from HoBao.
Caster Racing, TeamC and InTech have bounced around between several distributors but they both seem to have disappeared from the North American market as of late.
As far as kits with decent parts support goes I would consider the following brands:
PR Racing
TEKNO
Team Associated
Team Losi
Schumacher
XRay
AMain has a really good selection of respectable kits to browse
Best of luck!