In 50 years of cruising, I haven't seen that much of a change in the reliability of others. I could never reliably depend on them. Yes in a home port you can find competent people over time, but as you say, away from home it is pot luck, and given the median level of competence in the industry, the chances that they guy you picked out of the directory is competent is poor. No different now than 50 years ago.
What has changed for the better is the ubiquity of courier parcel service, nearly worldwide. In many places it is possible to get even obscure parts delivered quickly, even overnight. When my autopilot on the sailboat died 30 minutes after leaving the berth in Virginia headed for the Bahamas, and Raymarine offered 4 weeks turnaround to fix, I was able to have a used one from eBay delivered the next day (for less than the Raymarine fixed repair cost), all arranged on my iPhone. Did the same thing on a failed chartplotter. When the fuel lift pump quit on the trawler in the Wrangel Narrows going into Petersburg AK, and the only local Cummins mechanic was on vacation for 2 weeks, I was able to get a new pump flown in from Anchorage in a day.
I'd hate to depend on a warrantee requiring factory techs. You would be single sourced, and at their mercy. For me the bottom line is, if am depending on others to fix problems on a boat, I am going to be waiting in port and disappointed a large percentage of the time. Competent people are rare, and those that are are often backed up for weeks. Incidentally I find it no different in the RV industry.