Some choose to give half proficiency bonus on non proficient saves.Maybe PCs just need to be proficient in all saving throws.
An important note that is often missed by those talking about Dexterity saves as being top priority is that it isn't just how frequently a particular ability score is used for saving throws that matters, but also the severity of the consequence for failing the saving throw.
As a result, Dexterity might be the most commonly occurring, but it isn't the most punishing upon failure because typically the difference on a fail is taking more damage than you would on a success.
Constitution, Wisdom, and Charisma saves all have more dire consequences upon failed saves, things that take your character out of action for some period of time or actually impair your ability to do things, and thus should be considered at least equal in importance to Dexterity.
That all depends on whether the mathematical frequency of certain save types maps to the actual likeliness that they show up in your campaign, and how you view the difference between "save for half damage" and "save or your character not only can't do what you want for a few turns, but will be doing what their enemy wants instead."...but I find it highly unlikely that they're as serious as you allege.
Right there are you doing this thing where you look at my opinion - dex saves aren't as important as some folks paint them to be - and someone else's opinion that I don't share - that bear totem resistance is "crazy awesome" - and acting as though they are opinions held by one person. My opinion of the bear totem resistance feature actually matches more to my save opinion; half damage is cool, it's helpful, and yet there are other things with more impact and importance.I also find it humorous that the Dex save is apparently not that great because it "just" halves incoming damage, but stuff like the Bear totem features of Barbarians are crazy awesome...because they grant resistance to damage, which just halves it.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.