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.
Edit:
I like how incredibly controversial this is. I have successfully split the votes
Modern Chromebooks are typically slower and more resource limited than even quite old laptops ( like Thinkpads ). They may also be difficult to service and expand.
Chromebooks as a class may become common devices. Sadly though, I think most of them are destined to be e-waste.