However it seems to me that many of the projects are not about trees. Just to give some quick examples from supposedly reputable Canadian organizations:
https://planetair.ca/en/v2/comprendre.sn#projets
https://www.less.ca/en-ca/projects.cfm
For $24-$32/tonne (+ HST???), it actually seems affordable to offset my entire life's worth of emissions thus far. At least speaking as an overpaid tech worker. Say you are 35 years old, and you outputted an average of 15 tonnes per year (the Canadian average according to https://www.carbonfootprint.com), this works out to about $12600-16800 (+ HST???). Obviously I think the number should be lower for me given I'm younger, never owned a car, never cared for travel, and rarely buy things besides food, even before ERE -- I'm probably below the average of 15.
Would you consider working slightly longer to buy offsets for your up to date emissions, and to buy annual offsets going forward? It does seem like a meaningless gesture, but at the same time, I find I can reduce pretty much all of my actions to that train of thought

(Clearly if this is an important issue to you, reducing your carbon footprint is the preferred course of action. But I can't erase the past, and have difficulty going to absolute zero.)