Ah yes my very recent experience. We fully redid kitchen and went for Ikea (forsbacka oak, actually decently looking stuff, we will see about longevity). Our kitchen is very restricted, its on all 4 walls and everything needs to fit exactly, plus we have slanted roof on one side, making fitting a rather complex exercise.
So I bought bosch laser meter to be sure I don't mess up planning in their online planning software. We even asked Ikea to send a company that usually builds entire kitchen for them (aka their local partners), just to come for measuring and confirm my numbers (especially the angle of that roof, defines how tall and wide cabinets can fit underneath). It took forever, and the person doing measurements f*cked up badly, adding 30cm width to the place under the roof by mistake. He was re-measuring it but came with same number. I was suspicious of such a huge difference and luckily found his mistake, reverting back to my numbers (so we just wasted 1 month waiting for this company, even ignoring the fee).
Anyway, even with all their planning, in-person consultation, they messed up delivery and few items were missing, and they added few unnecessary items. Since delivery consists of 80+ brown boxes of all sizes that are just dumped on you, there is no way to find any mismatch out before building the actual kitchen. A lot of "fun" around that, I burned some vacation from this year on just chasing their mistakes.
Coming back to original topic - plinths or whatever goes under bottom cabinets to cover the gaping hole where legs are, were insufficient so we now have 0.5m hole there, waiting for item delivery while workers are long gone. Nothing is immediately available for pickup here, so waiting few weeks on piece of plastic weighting 1kg, 2.4m long, that costs cca 30$. Delivery - 100$, no way to even get it delivered to their shop, it needs to be a home delivery.
This is Switzerland, one would expect a bit better service in 2025 for their visibly elevated prices compared to EU all around. I did order the item in French Ikea instead, delivery was 'only' 40$. Not much competition for that price point here, but stellar quality service it certainly wasn't.
/rant