Sticky, tacky texture with less sweetness?

You could use corn starch.

People use corn starch to thicken thin sauces and get them to adhere better. I add it to try to rescue gravy when I have added more liquid than the roux can handle. I add it to stir fry with lots of vegetables in an effort to get the liquid cooked off the vegetables to congeal into a sticky sauce that is not all left in the bottom of the pan / bowl. When you cook down something with corn starch it gets gooey and tacky as you describe. But corn starch is not sweet.

Try making a sauce with corn starch and the flavorings you like. I have used a sauce pan for this. Whisk in some and then some more. When you get the consistency of the sweet sauces you are used to, try using it to coat ribs or chicken.

Note: taste it first. The corn starch sauces look great but can be astonishingly flavorless.

Ketchup produces a similarly sticky, tacky texture when used as a baked-on coating. If you use a ketchup with no added sugar, the result will still be somewhat sweet, but not nearly as sweet as with a sugary sauce.

Applesauce can have a similar effect. Again, use one without any added sugar. The result is mildly sweet rather than overwhelmingly sugary. For more control over the end result, make your own applesauce using tart apples rather than sweet ones.

Some other fruit and vegetable purees will work similarly. While I haven't tried these as a baked-on coating, I have made a variety of fruit leathers, and most of them go through a sticky-tacky phase. I imagine a puree of any winter squash, carrots, parsnips, plum, mango, or banana would work well. Of course the mango and banana versions will be quite sweet even without any added sugar. Some of the kinds of fruit that aren't usually eaten fresh, but only used for jams and jellies because of how tart they are, might be a good option. I'm thinking here of quinces, crabapples, etc.

Legumes and potatoes will probably not work - potatoes will end up like mashed potatoes, legumes get chalky and gritty when they dry out rather than sticky. Melons have too much water content for a simple puree to work as a coating, but you could reduce a melon puree by gentle simmering until it's thick enough to spread. If you wanted to experiment with a variety of ingredients with a minimum of effort, you could try using baby food.

Stickiness is a property of sugars, other foods are not really sticky in the same way.

As you say that you only want to reduce the sweet taste and not the actual amount of sugar, you are in luck. Sweet and sour is the only taste pair in which the presence of one really inhibits the tasting of the other, as opposed to all other taste combinations, where you get a mix that feels distracting at best. So, all you have to do is to add any acid to your existing recipe, until you have the taste you want.

There are a few cases where this might interfere with what you are making, but this is the minority. The one big area where you should avoid it is doughs and batters - it is OK to add acid to the filling of sticky buns, but don't put it into the dough itself. Also, you will see less browning in some applications, so you might consider adding it at the end if that happens.

Glucose (dextrose) is not nearly as icky sweet as regular sugar. It will sticky up quite nicely, without gooing up your taste buds. 1 to 1 replacement for sugar should work. Glucose is readable available online.