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
As an IT technician in a school, I have to repair Chromebooks of many different models on a regular basis, mostly from Dell and Lenovo. I haven’t seen one that I would consider durable yet. All of them use butterfly switches that break when a child rips off the keycap, meaning the whole keyboard has to be replaced. It is also common for the brass inserts into which the hinges are screwed to pop out of the plastic on most models due to rough handling. We also had one Lenovo model where almost every device we put into service developed a no power issue due to the same ceramic capacitor going short. Of course, the display panels are just normal panels that crack when struck - that is probably the most common damage we have to deal with.