If I could do it all over again, I would go for the paid critiques, but I feel I have gotten a tremendous amount of value out of doing the exercises even without them -- you can look at my completed lessons in my profile and judge for yourself -- and I have also been lucky to receive some valuable feedback from my peers who have taken the time to look over my work. It has been extremely useful to me to look at the completed work of other students and the official critiques they have received before I am done with that particular lesson. This will prime you to recognize certain pitfalls before you fall into them (or will teach you how to pull yourself out of them), and can give you a leg up on the lesson if you can implement some of the critiques and suggestions offered by the evaluators. I think this question ultimately comes down to two things: 1, whether you can hold yourself accountable to do the lessons as they are written without the social or monetary pressure to do so (from a cursory glance at your completed lessons, I would certainly say you can); and 2, whether you are the sort of introspective person who can look at the work of other students, then look at the critiques they have received, and then evaluate your work in that context in order to see if elements of those critiques might be applicable to your drawings. This is not a matter of judging whether your work is as good as the work of other students, but instead a more objective sort of evaluation where you esteem how your understanding of the tasks of that lesson is lining up with the work of other students.

It depends-- If you find some people in an active community (like the critique exchange on the drawabox discord), you could pretty reliably get good feedback. most people don't really have the consistency or time to participate in the free critique communities though, so it's often just throwing your submission into the void and hoping someone answers. most of the time you will get someone who is putting in a good effort to critique your homework, but sometimes you get people with copy-paste critiques or joke answers that don't make sense (or people who forget to mark your lesson as complete/forget to give revisions). I would recommend finding a community of people to critque each other's work (discord is a good place) or just having a good way to ask for critiques (begging on discord sometimes works.)

this does seem like a lot of things to do to get free critiques, but if you find a way to reliably get critiques for free then it's really just a matter of waiting. of course, the patreon basically saves you a lot of time by giving out critiques really quickly that are guaranteed to be good, so they are obviously worth. but I can see that you finished lesson 2, which is still pretty early in the course. a lot of people struggle and take a long time to finish the course, so you could probably try and reach the halfway mark before you really decide or figure out whether you can really do this in the long run.

ultimately, drawabox is good mainly because it provides a structure for studying art. paying will get you a lot of benefit, but the things that matter more are completing the course properly- like the 50% rule, warmups, and most of lesson 0- things that no one can really monitor you on, paid or not.

whether you get official critiques or not, I think you should still read other critiques before and/or after your lessons, because they can open you up to new insights that you may have not considered before and can look out for.

I hope this helps give a bit of clarity