How prevalent is the dock scratching the Nintendo Switch's screen?

Don't worry too much about this. I'm pretty sure a big part of the "scratch fiasco" is websites and YouTube channels looking for ad impressions (and money), unfortunately. I've removed/docked my Switch several times since day 1 and I don't see any scratches or even smears/traces on my screen (with a screen protector).

Looking at my dock, I simply see no way the dock alone should be able to scratch the screen, because there are two plastic guides with small rubber pads to keep the screen away from the dock, but they don't really have any sharp edges.

Of course they might in theory still scratch the screen, especially if you're just "throwing" the console into the dock or if there are bigger dust particles in there (maybe even sand from your hands?).

As such I think adding any good quality screen protector should offer you enough protection. It doesn't have to be tempered glass, even just a not too thin foil should be sufficient. If you notice damage on it, replace it, otherwise just enjoy playing.

Edit: Also, something I noticed the very first time I saw that now "famous" picture of the scratches: Their orientation is completely inconsistent and doesn't make any sense, if you assume the console is inserted in a straight way as intended. Just look at the scratches highlighted with a few lines:

This looks – at least to me – very deliberate, rather than random usage. Also wouldn't you assume there to be one or two scratches before you notice them? Rather than waiting for 10-20 to appear?

It all depends on what you're going to do with your Switch.

If you're planning to use it as portable console then you'll just have to buy a charger which will not require to put the Switch in it's dock each times, so no problem.

But if you're like me, and you're going to use it with an external screen then there are a few problems.

I was first expecting to let it in it's dock without taking it out except for rare occasions, but you have to keep in mind that except if you're going to buy a lot of accessories, for example, you'll have to charge your playcons. And to charge them, if your dock is put with your others consoles in a place not that easy to reach, you're going to take off you're Switch, put the playcons on it put it back again until you play next time.

Another thing : you can't totally switch off the console using the menu. So once again, if you want to power it off you'll have to take it off the dock, switch it off and put it back in again.

So I'm someone like @sir adelaide described. I'm really careful with all my consoles, but even after having bought a screen protection, I really dislike this dock as you have to search the right place for the Switch to be well connected and for that, you move the console int it's dock a few times.

I don't have any scratch yet, but I'm sure if they don't release an adapter to connect the console to a screen without the dock, or if I don't buy something to charge my playcons without having to attach them to the Switch, there is bound to be some scratch soon.