If you're not going to declutter, an apartment isn't for you. However I wouldn't dismiss apartment living, there are a lot of advantages for older people - no external maintenance, they're usually easier to heat, often have nice views, and also the point mentioned earlier about it because easier to lock up if you are going away for a while. There is a big difference between a well-run apartment block with an active management company who will clamp down on anti-social behaviour, and what many of us might have experienced when we were younger or on our holidays in costa-del-whereever.
Personally I think decluttering is a good way to make a bit of a break with a previous life and start a new one. 70 is not so old any more, and fingers crossed you have plenty of life left to lead. I took a bit of a Marie Kondo approach to previous house moves, and threw away (nearly) everything I was keeping "just in case" and kept only the things that brought me happiness.