In effect, is it really that different to a fine? It seems to have a couple of advantages, though: it's easier to collect, and it's proportional, so a person who can afford a fancy luxury car pays more than someone in an old banger, without the complexity of having to evaluate their income and savings.
Guitars aren't complicated machines, and there's no special reason that a Squier shouldn't stay reasonably in tune, as long as it's set up properly. However, factory-produced guitars almost never come properly set up or with a well cut nut. The nut in particular is important to tuning stability, especially when using a vibrato system.
There's a lot of difference between Bigsby, strat, Floyd Rose, and Jazzmaster systems, but none of them is indispensable. Many people go their whole lives without ever owning a guitar with a "tremelo"/vibrato.
There are some techniques you can't implement without one. On the other hand, on a hard tail you can do other things like bending one string in a double stop and not have the other go out of tune. If you break a string you can keep playing until the end of the song without being completely out of tune. You'll probably find that you have longer sustain. Palm muting is easier.
tl;dr go ahead and buy a hard tail, you won't regret it.
Often these little practice amps are better than you think, but are held back by the stock speakers and cabinet. I got a Fender 15G free when I bought a guitar years ago. Recently, I populated the circuit board for reverb, added a spring tank, and swapped in a Celestion speaker, and it's now pretty good.
But a few weeks ago I ended up with another free Fender 15G! This time I think I'll build a new cabinet for it as well as adding in the reverb.