Is there a situation in a street fight where high kicks would be the best choice?

Lots of them. I once had an opponent charge at me from about 10 metres away, right hand raised obviously intending a big hook: I delivered a gliding side kick to his chest - laying him flat. If I'd wanted to hurt him seriously, I'd have gone higher. It had the advantage of closing the gap towards him and engaging him earlier than expected, he had no chance to adjust his movement. The longer reach of my leg meant he had no chance to throw a punch earlier (he was taller with more reach, so it was best not to give him the chance as I'd be the one who had to dodge or deflect it before making contact myself).

This reach aspect - the contrast with arms reach - is an important benefit of kicking, be it high or low.

Simply having a larger variety of ways to attack the head is a fundamental advantage.

Consider full contact karate, kickboxing, Muay Thai etc. - I've not heard of rules under which competitors have to kick high, and yet it happens quite a lot, obviously because - on balance - it helps win fights. While there's massively more variety in street fight situations, there's plenty of times when you've got good footing, and enough awareness of the situation to make informed, rational decisions about the pros and cons of using high kicks, or any other techniques.

Front kicks / mae geri in particular are very easily and powerfully delivered at chest or chin level with little compromise to your position, it's easy to watch how the opponent's moving and decide whether to kick, the recovery is fast, you can keep your hands in a decent guard and block or punch freely. If they're moving to stay just out of arm's length, it's easy to bring a front kick through.

Another benefit of kicking is that you're likely to be wearing shoes, and a kick to face doesn't have the risk of teeth cutting you and their blood getting onto those cuts, the way a punch to the face has.

Why not prefer low kicks? With low kicks, you have fewer chances to lose your balance, fewer chances to miss the kick, and higher strength in the contact.

I disagree with "fewer chances to miss the kick", if you consider low roundhouse/turning/mawashi geri jammed by a raised leg a miss. Further, given humans' centre of mass, if you kick between the waist and sternum the defender can't just pivot out of the way with a switch-step, or lean their torso this way or that.... it requires a good block or significant power against the ground to move their core.

"higher strength in contact" is true for roundhouse kicks, but isn't true of front kicks, side kicks, spinning back kicks (all of which have greatest power around chest height), spinning hooking kicks with the heel (which most naturally and powerfully target the head), vertical/slapping/uchi mawashi and crescent/soto mawashi....

Even if you get a low kick in, they're less likely to end a fight than a strike to the head. If your opponent is a conditioned full-contact fighter, they can probably take many minutes of such strikes, and - in street fight situations sans gloves - it's the head strike whether with hands or feet, that's likely to be decisive.

In addition, you don't have to be flexible for kicking with a low kick.

Sure, but that's a bit like saying "we shouldn't punch because some people have soft, unconditioned hands". If you're not flexible, either put the work in at stretching or don't use high kicks - whatever works for you. There are technical aspects that affect how much flexibility and leg strength is needed for high kicks too - for example with a side thrusting kick, the right footwork sling-shots the leg using hip rotation, making it easy and effortless to kick high, but of course such footwork may constitute telegraphing, depending on the situation and opponent's skill.

While a low kick is a great go-to first option for a street fight, it's not a good idea to take high kicks off the table. Still, nobody can be a master of every martial skill - if you've been developing other skills, it may be better to stick with what you're comfortable with, but under-estimating the utility of high kicks is not wise, even if you're not planning to use them yourself. If you think you perceive disadvantages, get in the ring for some full-contact sparring with people who kick high, and put your ideas to the test. Whatever you learn there will be worth more to you personally than all the replies here.