I've had the same experience. My IBM ThinkPads had great keyboards. Lenovo modernized them, but introduced a bunch of quality issues.
Oh, and I forgot to mention the most annoying issue of all: the TrackPoint still drifts on every modern ThinkPad! This was a big issue on IBM ThinkPads, and Lenovo hasn't bothered to fix it in all this time. I've had it on my 2018 X1 Extreme, and now on this 2025 X1 Carbon. It's enfuriating that such a high profile functionality has such a glaring issue for such a long time. Just shows Lenovo's lack of care and attention for this brand.
Oh, and I forgot to mention the most annoying issue of all: the TrackPoint still drifts on every modern ThinkPad! This was a big issue on IBM ThinkPads, and Lenovo hasn't bothered to fix it in all this time. I've had it on my 2018 X1 Extreme, and now on this 2025 X1 Carbon. It's enfuriating that such a high profile functionality has such a glaring issue for such a long time. Just shows Lenovo's lack of care and attention for this brand.