I think you've hit the nail on the head recognising it's very location dependent. In Northern EU, if I built a house alone or with little help I'd definitely go for AAC (autoclaved aerated concrete) blocks. They are relatively cheap, light weight so easy to handle and you can have a less "serious" foundation for them as opposed to silica blocks, if you buy from Aeroc or some other known company the dimensions will be spot on. You make cuts using a special saw (https://www.toolstation.com/irwin-concrete-hardpoint-saw/p43...) and you don't need a concrete mixer on the plot as these can be glued together, so basically you don't need water and electricity on your land and can transport the tools in and out in your wagon/pickup every day. In addition you can grind away imperfections, even cut new doors and windows later because the material allows for it. The downsides are poor sound insulation and needing special anchors for hanging stuff. It's also very easy to make grooves for wiring and pipes, which again, can be done alone and without electricity https://i2.wp.com/elektroznatok.ru/wp-content/uploads/2017/0...

Expertise required is getting the corners up precisely and being able to use a laser level and a string. You don't make ceilings/floors from these, the best option for multi-story house would be to have the floors done from a pre-fabricated concrete blocks which a crane would put on your walls https://baltparma.lt/39-large_default/perdangos-plokstes-pk...., this will give very stable floor. On the other hand, in US there's lots of framing expertise as you're saying and the options I've laid out are probably not as accessible.