If you’re worried that your Drobo will fail and are looking for another solution, unfortunately you will likely have to purchase something other than Drobo. Drobo units have been out of stock everywhere since early 2020. Most people who are migrating away from Drobo 5N and 5N2 are opting for Synology, but that is for NAS (Network Attached Storage) units. Yours is a DAS (Direct Attached Storage), for which alternatives are less common. On Reddit, some people talk about OWC Thunderbay 8 as an alternative that allows Drobo-style mix and match drives (i.e. not all drives must be the same capacity). The bare unit seems to have an MSRP of USD650$, but I’ve only ever seen it for about USD750$ on Amazon. Or about 850 euro from Amazon.de (Amazon.fr seems to be sold out) with free shipping.
About your overheating unit, you might want to check that the rear fan has not seized. It is not uncommon for this to happen on Drobo units (it happened to my Drobo FS). That could cause it to overheat. Those fans are pretty standard PC case fans (120mm), so you could probably replace it yourself if it is broken, as I did with my FS.
I hope that helps!