Despite using a version of the Linux kernel in ChromeOS, Chromebooks don’t always have the best hardware (ie. driver) support from the mainline kernel used by most distributions. That’s why there are niche distributions like GalliumOS which provide tweaks to support the touchpad and audio devices in many Chromebooks. It’s similar to how Android is Linux, but it’s not standard Linux as we are familiar with (so the hardware support is different).
Many Chromebooks have really poor specs: low-wattage CPUs, small amounts of storage, low amounts of RAM. While they may be newer, they are actually probably less performant than older laptops. This has changed in recent years with the new Chromebook plus program (or whatever it is called) which mandates a reasonable set of baseline features, but that is talking about current Chromebooks and not the ones from the COVID era.
Related to the previous point, many Chromebooks are not serviceable or upgradeable while Thinkpads and some recent laptops are. You are unlikely to open up a Chromebook and be able to replace say the RAM or SSD, which would be a show stopper for a lot of people that like Thinkpads.
So… unfortunately, I think this take is a bit of a miss and I dont’ really see it happening. I would be happy to be proven wrong though since my kids have two Chromebooks from the COVID era :}