It's 2021, and we still have to remind people that RAID is not a backup?!
Every time someone tells me tape is obsolete, and I should just use disks or The Cloud! to do backups, I ask how they intend to make offline backups of up to 3PB of data (it's about 1/3 that used currently, but increasing year on year, and I expect we'll top out in a few) that is currently air-gapped, with an off-site requirement. In terms of rack space, power, and cooling, we can't expand anymore. Tape (mix of LTO-5/6/7/8, currently) is about the only way we can meet our requirements.
In just terms of physical *weight*, disk is impossible. Imagine how much, say, 64 16TB HDDs weigh vs 87 LTO-8 tapes weigh (roughly 1PB each, ignoring the compression factor of 2.5x, which I never actually see), let alone physical volume... Add in the additional mechanical complexities of needing all the control hardware on-board with disk, and things like vibration during transport becomes a major thing.
Let's not forget that, many times in the past, HW RAID has been shown to be... less than ideal, shall we say. So much so, that I wouldn't trust HW RAID further than I can spit, and would rather rely on Linux SW RAID in terms of reliability. Tapes, I can pull as they fill up, and ship offsite. Drives in a RAID array have to all be pulled in tandem, or you break the array (and have to rebuild later, with its own plethora of problems), so it's still significantly less convenient. Space, as well... I can fit 80 12TB tapes in 4U, in an easy to access fashion, but putting 80 HDDs in the same amount of space (maybe outside a Petabox) isn't really doable, especially with power and cooling.
All in all, tape isn't going away anytime soon. Anyone who says otherwise is either deluded, inexperienced, or trying to up-sell something unfit to task...