It is absolutely worthwhile doing any of the immersion techniques you mentioned. Volunteer work would probably be the most important thing that you're missing. And I don't mean 'gap year help build a library' kind of volunteering, that stuff is implicitly pre-college, instagram stories and expat heavy. I mean exchanging a few hours of light work for bed and board (the language exchange is free). You can be pretty picky in most countries with sites like workaway or helpx, and probably find a little family to hole up with and do work remotely. And yes, you will find (single) people of all ages doing this.
EDIT: i see I'm supposed to say how traveling changed my life personally. pretty simple if you are me because studying language is my favourite hobby, and, as an amateur linguist, it is essential for my life satisfaction to immerse in something new every couple of years.
EDIT: i see I'm supposed to say how traveling changed my life personally. pretty simple if you are me because studying language is my favourite hobby, and, as an amateur linguist, it is essential for my life satisfaction to immerse in something new every couple of years.