Try
Musicolet.
With this app, I set it to a folder and just push play and it will pick up where you leave off.
So, I just open it, and then push play and that's all.
It has soooo many options, though, I don't know all of them.
It doesn't have any ads. Also, and you'll like this, you can simply touch the cover art (great big area) to play/pause.
It doesn't have popups and no surveys or questions. You can toggle shuffle.
I never use the search.
There's another called Voice, but I can't find the link for it.
Mortplayer is quite nice, but it crashes when you change folders if you use a newer Android.
VLC is okay, but can be annoying.
I've tried all sorts of music players and audiobook players.
For audiobooks I use
Pocketbook Reader - it remembers where you leave off and you can use it for both ebooks and audiobooks.