Yes but spreadsheets can't observe why while having good stat the IS2 is barely used. So maybe its because other unit's stats, maybe because of the meta, or build order, or cost etc...
I take again the Sherman example, it has on paper good AT stat, but once you compare it with armor it faces they suddenly don't look like so powerful.
This is true, of course, and should be obvious enough for everyone to not warrant a disclaimer. What spreadsheets, or any amalgamation of stats for that matter, allow you to do is to get insight into things you can't (or only with great difficulty) deduce from gameplay alone. Sure you can get a rough idea how likely it is to pen a PzIV with a Sherman, but without looking up the exact value from some external source you'll likely never be able to narrow it down precisely due to the huge influence of RNG. But values like chance to pen, chance to hit, scatter, etc. are essential for any sort of reasonable comparison to be drawn, after all that's exactly why we have and need all kinds of stat pages, spreadsheets and calculators. That this can't give you all the answers needed to explain why, for example, the IS-2 sees less use than the Tiger is undoubtedly true, but no one (at least not me) claimed anything like that in the first place.
Let's think about the parallel between Tiger and IS2. On paper they have the same AI DPS according to MMX, but both tanks don't have the same speed, could it be possible that the Tiger being able to close the distance faster and disengage faster is used more aggressively and thus regularly at medium range while the IS2 being slower is more likely to shot at max range making the difference people are seeing. Or that a good part of IS2 AI dps comes from the dushka which is modified by the constant late game yellow cover all around the map.
My point was only there, Stats are indeed a good 1st point to take in account but you can't stop by it and say everything is fine or broken because stats are ok or not.
Saying that both tanks have roughly the same AI DPS/KPS was of course a gross oversimplification; in reality there are indeed various ways both tanks differ in terms of their AI performance based on squad formation and model count, distance, cover, alpha-strike capabilities and so on and so forth.
However, it should also go without saying that a complex analysis like this would be quite far out of scope for a simple reply as to why I think both the Tiger and IS-2 are roughly equal in terms of AI. (Again, if you are really interested in the details, such as what difference MGs make in yellow vs no cover fights or which tank is more effective in killing models with the first shot you can look it up over
here).
I fully agree to the last part, though. Nonetheless I still prefer to make assumptions and judgements based on stats that may paint an inherently incomplete picture than to dismiss these kind of objective data alltogether and rely fully on game sense or intuition instead.