Why pay? They really aren’t that much more difficult. They have a few more expensive parts but back in the day so did those older engines.
There was not much I couldn’t fix on my old ‘68 firebird that a nail file and a screwdriver couldn’t handle.
The worst thing that most “modern” cars the engine is sideways so the high wear parts (and the stupid timing belt) are jammed up against the left wheel well leaving no room to work at all. So discouraging. I could change the water pump, timing chain, alternator and power steering pump by myself in about two hours and cost maybe $200 in parts on my ‘68 Firebird. That same amount of work would cost 2,000 dollars or more and I would be without a car for probably 2 days. It is ridiculous.