It depends on the situation. There’s plenty of games that made the DLC era notorious by putting out games with only half the content as prior games. In the case of Forza Horizon, I feel they’ve provided substantial content in the base games, at least as far as maps and modes.

I will agree with OP about the number of DLC cars though, because it’s excessive. I wish I could filter out DLC and stop being teased. It’s particularly annoying when basically and entire manufacturer is DLC (Porsche in FH4 I think) or when some 3rd party sponsor brand drops a ton of “sponsor edition” cars. Maybe I’m just out of the pop loop but I do NOT need Hoonigan cars when I can modify any of the base cars to be stupid fast. I rest my cane.