So, it sounds like COP26 was a big waste of time and jet fuel.
Jet fuel, yes. The delegation sizes were outrageous. But I think it's worth considering the purpose of a COP.
Most action happens at the local/regional/state or provincial level. But that will always be uneven within any jurisdiction unless federal policies/legislation is put into place. That eliminates laggards. Take Australia for example, where the entirety of the country is covered by a (meaningless) net-zero by 2050 commitment, but something like 3/4 of the population lives in an area that is covered by fairly strong interim target with supportive policies and procurement. It ends up translating to a 37-42% reduction of GHG emissions below 2005 levels, but the nation's own international commitment is only 26-28%.
So that's great, you might say. They'll overshoot their commitment. But governments don't know as much as you'd think, which is why there are so many advocacy organizations trying to share the reality of the situation. Other nations' commitments are in most cases going to be based on the promises made by others, not by the reality of the forecasts. So those national commitments matter the most for international equity, with COP decisions (and others) doing the same thing that national policies do - eliminating the laggards, but in this case through political pressure and market bending rather than policies that cover everyone.
These negotiations are
intensely legally and technically complicated. When you see things like "calling upon" countries to accelerate the phasedown of unabated coal power, it's a signal rather than a rule. It tells you that your peers will hold you to this, and through this same forum. Its success will rely on the other pieces such as finance.
That coal piece is actually a huge deal, and while it was weakened at the last second, that was out of equity rather than lack of desire for a full phaseout. In terms of keeping a chance of 1.5º in sight, COP26 was fairly successful. But on the other pieces that are needed to support equitable implementation of that goal (finance, separate finance for loss and damage, market rules) it was a failure.
Again though, this isn't the only forum. You see a lot of bilateral agreements that help, though I tend to roll my eyes at the G7 and G20.