What % of ACTIVE PLAYERS do you think have:

Dragonite: 95% (18months of Dratini in the game, anyone who has been active for most of that time should have caught or hatched enough Dratini to get a Dragonite by now)
Tyranitar: 95% (6 months of Tyranitar being the most popular raid boss outside of Legendary's combined with being out for almost a year, most players should have had some combination of Raid Bosses or Hatches to get a Tyranitar)
Unown: 20% (*bleep* you, Niantic. *Bleep* you. No, I don't have one - only 2-3 of the people I raid with regularly have one. Most of us have written it off.)

Active players being those that RAID at least once a week,

Dragonite: 90% (Common 10k hatch until 3rd gen)
Tyranitar: 85% (Even though its a raid boss many haven't done TTar raids!)
Unown: 25% (Scanner, events)

This is in MY area. YOURS may be different.

I still don't have a Dragonite (75%) because drat ini are essentially non existent where I am and I still haven't hatched a good one.

Tyranitar (99%) is by far the easiest, I hatched a 93% Lavitar as my first 10K after Gen 2 was released and now that is not so special as they are in Boss battles everywhere.

Unown (10%) I have one (H) only because I was alerted via friends in discord. Never would have found it on my own. I think it's pretty obvious there will be some sort of Unown even in the future.

90%
90% (think of rural)
20% (events/scanners)

Dragonite: 90% (common generalist and defender with high DPS, I don't have one currently, though)
Tyranitar: 95% (can be obtained in raids, common generalist, high DPS)
Unown: 5% (still extremely rare for people including me, if not using scanners)

If using scanners:
Dragonite: 99% (scanners show the Dragonite IVs)
Tyranitar: 99.9% (scanners show the Tyranitar IVs, and even Tyranitar raids)
Unown: 95% (which scanner doesn't show Unown)

90% Dragonite, 95% Tyranitar, 20% unown.

My idea of active player is someone who raids more than once a day and their trainer level is in the high thirties, if not 40. Given that, I'd be very surprised, if they don't have a dragonite, or Tyranitar. Some probably don't have an unown. Most won't have some of the regionals, and some of the gen 3 rares.

If during a raid, I encounter someone who doesn't have one of the meta relevant attackers, I'm inclined to think of them as a casual. This probably has something to do with where I live, a San Francisco suburb.

If you have a different definition for, "active trainer", I would adjust my expectations downward, accordingly.

Dragonite- 95% fairly common for fully evolved Dragonite to spawn (I have caught 10 without the aid of a tracker).
Tyrannitar- 75% the people who raid frequently all have them but almost no one else does (larvitar spawns are basically the rarest thing besides unown around these parts- I've hatched or caught only a few more- 12 than I've caught Dragonites).
Unknown- 0% I am nearly positive there has never been one spawn in our area (or at least no one stumbled upon it when it spawned if it did). I've only seen 2 in gyms and they were both from accounts that are known spoofers.

I have no idea about % but I do not have any of them, I'm level 27. Reading about Pokemon Go on the internet makes feel like the only active player in 2018 above level 25 without any of those Pokemons or a legendary. I have hatched a Dratini and a Dragonair but haven't managed to get enough candies for them. I don't have Larvitar

I don't even have a Machamp and just managed to beat a Porygon raid for the first time today only thanks to my four Hariyamas between 1800-2200CP but even Makuhitas have declined in appearances after the holiday as with Eevees that used to more common. Now It's mostly the parade of Pidgeys, Hoothoots, Weedles, and Rattattas, along with occasional Roselias and Marills. For some reason Caterpie is rare though.

I do have one 91% Gyarados that took me about 6 months to evolve but it's still only about 1900CP, with Waterfall and OT. Unfortunately I don't really get to use it much because my highest CP Pokemon happens to be a Vaporeon at 2400CP and I have a few other Vapes I evolved when Eevees used to be more common.

However I do have a Pikachu nest near me right now so I have that going for me, which is nice. Also it's still a pleasant surprise when I do fill out Pokedex out of blue, as I happened to catch a Lapras and a Venusaur out in the wild in the last few weeks when I least expected it. I just caught a Granbull for the first time today and even that lowly Pokemon made me so happy despite having the worst moveset possible with Bite and Close Combat.

So if you are unhappy that your latest Kyogre has only 82% IV, keep in mind there are still players like me.