I am running a LND node for four years and had just one force-close which was initiated automatically by the remote side for inexplicable reasons. The mempool fees where low back then and there were no HTLCs to be settled (expect for the closing tx itself) so I didn't really lose a significant amount of sats. But I indeed know people who had a lot of force-closes within a short period of time. It can be painful if this happens in a high fee environment. It gets even worse when there are lots of HTLCs to be settled (thus I limited the maximum amount of pending HTLCs to 5). But overall my LND node runs pretty reliably.