I love travelling and holiday-ing alone.
Agree there's a few places in the world probably better with a companion .... Las Vegas being one!
I usually tend to take advantage of friends living overseas .... and travel alone to their part of the world, then meet up or base myself there. I did USA (vague!) last year..... staying each of 3 weekends with a good friend, then Mon-Fri one week touring their state, then mon-fri the following week at an all-inclusive beach resort. Really is best of both worlds for me.
I'm happy to strike up conversation over a pre-dinner G&T if I want company / conversation. Or if you bring a book / kindle and concentrate on that, surprisingly few people actually notice.
I take the same safety considerations as I would at home, ramped up a bit if only because I may be unfamiliar with an area (and possibly language).
Don't get me wrong, there's time company would be good ... of whatever flavour ..... but I'm not going to not travel just because I'm single and / or no kids and / or friends not available.