To reply to the OP: There’s been a big movement in the last 10-15 years in the HVAC industry to add more technology to the equipment. I suspect that’s in response to consumer demand as well as an effort on the part of manufacturers to have more proprietary parts content in their products. (They get the repair parts market).
Technology has indeed improved average system efficiency but at the same time equipment expected life cycles are now much shorter than what used to be considered acceptable. The current crop of high efficiency mini splits or wall mounted boiler mentioned in the OP are great while they’re running well but can be very expensive to repair when they’re not.
The problem with the high level of technology is that in many cases the service base to support them isn’t there. For example, there’s another thread on the site today about getting competent service for mini split heat pumps. To pick on mini splits or high efficiency boilers (etc.) some more, try pricing up one of the proprietary electronic boards that make them run when outside of warranty.
Personally, I’m not up for spending tens of thousands of dollars every 10 to 12 years on HVAC equipment. Count me in the KISS crowd and I can do my own installation and repairs!