So, I found a list of most of the armors in TotK, and I thought it might be interesting to give a brief listing on numbers and how many armors there are in the game.

Breath of the Wild contains 16 full sets of three in the base game, and another 16 individual pieces (such as the Old Shirt, Monster Masks, and Gerudo jewelry), for a total of 64 armor pieces that can be found.

BotW's DLC adds an extra 5 sets and 7 individual parts, for an additional 22 armor pieces in the game - that's a total of 86 armor pieces that can be found or purchased in the game without Amiibo.

BotW has an additional 6 sets and 5 individual pieces that are exclusively accessed by Amiibo - that's a total of 109 armor pieces available in the game.

Tears of the Kingdom does not have any Amiibo exclusive armor pieces. There are armor pieces that can be acquired using Amiibo, but they can also be found in treasure chests in the game world.

Tears of the Kingdom brings in 11 new sets, and 7 new individual armor pieces, that are NOT available in Breath of the Wild. That's a total of 40 pieces, available in the base game, that are not available in Breath of the Wild. This includes one new set of "Amiibo armor" that is also available to be found in the game. It also includes the "Hair Band" that allows you to tie your hair up like in Breath of the Wild. Of the new full sets, 9 of them feature completely new abilities to Tears of the Kingdom, and one of the individual pieces has a "similar but new" ability. The 10th full set reuses an existing ability, but is necessary to complete a sidequest (think of how the Gerudo Set allows you to gain access to Gerudo Town in Breath of the Wild), and the 11th is the "Amiibo Armor". So a total of 29 armor pieces have an ability that was not seen in Breath of the Wild.

12 sets from the BotW base game return, as well as 14 individual pieces, for a total of 50 armor pieces. 23 Amiibo armors and 18 DLC armors return as well. By my count, which may be off by one, there are 4 sets and 4 individual armors (16 total armor pieces) that were in Breath of the Wild that are NOT in Tears of the Kingdom. This includes the armors you find on the Great Plateau, the Nintendo Switch shirt, the Salvager Set (Xenoblade Chronicles 2 armor), and... apparently the Hero of the Wild set? I suspect I'm wrong and the Hero of the Wild set actually is available, but hasn't been recorded yet. There are a couple of other sets that I haven't mentioned to avoid spoilers, but I'm 99% sure wouldn't be in the game.

At launch, without preorders, BotW had 64 armors while TotK has 131. I don't really know if this "means anything" but it sure seems to me like TotK uses armors more for quest and exploration rewards.