Are old ThinkPad laptops still reliable

We have about 150 Dell Latitude and Inspiron in circulation in a very rough environment (utility meter readers and installers).  Most are 5-10 years old.  Yes, they come back for repair for cracked LCD and keyboard issues, but they are easily repairable.  I don't bother with Dell's drivers except BIOS as the Windows update grabs the most current anyway.  We took some 15 year old Dell's and use them for training, indestructible.

We have a couple of HP's and they are nothing but trouble, even in office only environment (finance department).  Very delicate and tech support treats me like less than dirt for warranty repairs, which is very disappointing.  I used HP in former jobs and swore by HP at that time, however the difference between then and now is profound.  Lenovo at my previous job was difficult to get parts as they were all about voiding the warranty.  There was a recent Spiceworks thread on right to repair and I think Lenovo could be lumped in there in the negative column.

We got a couple of Microsoft Surface and had moboard issues.  Turns out the solder crystallizes and shorts adjacent traces.  Roughly 25% were affected.

As I said above we have a bunch of older Dells and if you check the Win 10 compatibility list they are not compatible, yet I upgraded them from Win 7 and all is well.  The issue is active-x on the video card.  I had one with a Skylake that I couldn't downgrade to Win 7, but that was expected.

Another option might be Panasonic Toughbooks and Toughpads depending on your environment.  We have about 200 Toughpads, G1's and H2's.  The toughpad issues are severe abuse and generally just need to replace the screen protector which is 3 for $10 on Amazon.

For SSDs and RAM I get Crucial.  Not a single failure in roughly 350 units.

We have been looking seriously at the Dell Dex docks for Samsung phones.  With Office 365 cloud based in One Drive the Dex makes road warriors truly mobile for surprisingly low cost and a lot of functionality.  Why issue a phone and laptop when you can just issue a phone?