Tanks are missing a significant amount of resistances from the old mastery system

When Runes Reforged came around, players lost the ability to add stats to champions with a rune page. To compensate for this, champions were given stats along the lines of their more common rune pages. AD champs and tanks were given 9 armor and ~9 AD, and mages were given the scaling health they would have gained from yellows and base health from quints.

That's all fine, except ...

The new rune set bonuses also give stats. Primarily, offensive stats.

About 400 gold worth of offensive stats to start the game off.

What do tanks get? 15 health. 40 gold worth of health to start the game with. At level 18? still not even 400 gold of health.

Oh but hey you get 80 gold of health to start with resolve/inspiration. So you only have to get to level 10 to get the same amount of stats your carry lane opponent fucking started with. Surely nothing catastrophic or meaningful in terms of farm disparity could happen in that time span.

Compare this to the health and resistances offered under the prior rune and mastery system. We'll assume the tank is taking the equivalent reds and yellows to reach those stats the same as currently.

78 Health from Quintessences the Veteran's Scars mastery grants 50 health, totaling to 128 And while not common for a tank outside of support, the Stoneborn Pact keystone grants 5% extra health, a minimum among the tanks with the other 128 already assumed being Shen and Poppy starting at 540 + 128 health, which grants them an extra 33.4 health

A minimum total bonus health therefore of 161.4. THIS IS ALREADY MORE HEALTH THAN RESOLVE+ANY OFFENSIVE SECONDARY GRANTS AT LEVEL 18

And the masteries for resistances:

At the lowest end we get a passive +5% bonus armor and magic resist. This was revamped in the new system as Conditioning, but it's important to note conditioning is a little bit better late since it grants 8 flat resistances and gives its 5% to total AR and MR instead of just bonus, but that it is literally worthless in the laning phase where tanks need to rely on stats the most.

Next row down is Siegemaster, granting 8 resistances while defending an allied tower, or alternatively, tough skin to make auto trading a little more favorable. Both are good but we'll just go with Siegemaster for the raw stats.

Next up is a favorite to protect from burst, Fearless. For the first 2 seconds of combat, Fearless grants and extra 1.5 per level +10% bonus AR and MR before going on a 9 second cooldown. This mastery was a great boon to make trading possible for tanks in the early game, and to give them extra engage power in team fights later.

Finally, Legendary Guardian, which grants 3 AR and MR for every nearby enemy. In a solo lane this would be just 3, while in a duo lane or amidst a gank it would be 6. When ganked in a duo lane, 9, and in a full team fight a whopping 15 bonus resistances. We're just looking at the power granted for laning though, so 3 it is.

Added all up, the (effective) early resistances offered by the old system were 8+(about 5 on average from fearless during early laning) + 3 + 9 = 25, x 115% = 28.75. The 9 here is from runes, while the 115% is from fearless and Unyielding's bonuses.

The new system gives us that 9 from our runes, but is still missing nearly 20 resistances for use in the early game.

Combined with the lower early health, tanks are missing out on a huge amount of resilience at all stages of the game, but especially early, and aren't getting compensated for, all while carries get their missing AD/AP wholesale, more of the stat from rune bonuses, and even more yet from individual runes.

It's no wonder why tanks are just saying "fuck it" and going nearly full damage, because tanking hits with anything besides massive %damage reduction isn't a viable option.