Maybe this is a hot take. However, a lot of the Chromebooks that were deployed by schools during covid are build like tanks while being super lightweight and having great battery life. Meanwhile the old thinkpads are 10 years old and are probably starting to wear down. Many Chromebooks support coreboot these days so theoretically they have the potential to be more private and secure. Some of them are also arm which means that they are more efficient from an architecture perspective.
I have been repurposing my EOL Chromebook, and I don’t think they will ever be able to compete with ThinkPads. I like my Chromebook since it is so damn small, however the specs are really bad. And everything is soldered right on the motherboard. So I have 64GB storage (plus an SD-card) and 4GB RAM. I have enabled ZRAM so the CPU is helping out a bit. But even so I struggle with the memory. Browsers are such memory hogs!