My home was built in the 1970s, at the same time as most of the others in the neighborhood. There was a fire that gutted about half of the home in ~2008, and as a result the entire electrical system, internal plumbing, insulation, and most of the windows were replaced.
Because of this the home was priced like others from the 70s, but I'm very confident that I won't have any major and unexpected structural, electrical, or plumbing issues in the near future.
The only real downsides are that there isn't a basement (I have a dirt crawlspace, with a ~10x10 area dug out enough to stand up for the water heaters and such), and I own one of the few homes inside city limits with a septic tank.
City code prevents me from making major repairs on the septic system, so within the next few years I'll need to connect the home to the sewer. That's going to cost between ~$500 (if I do the work myself, which will probably take about a week of full-time, dirty work) and ~$10k (if I just pay someone to do it all). I'll likely end up hiring someone to dig the trench needed in the front yard and in the crawlspace but do the rest myself.
Older houses tend to be much higher quality. You can obviously find custom homes or more expensive homes built with better materials, but according to my contacts in the home building business, ~90% of homes being built right now are the bare minimum required to get the customer to buy, and most of them wouldn't meet regulatory requirements because the inspections just weren't done.