Baby Led Weaning/Feeding

I've looked into this alot and just want to know some of you all's experience with it. On Instagram, I see so many babies successfully doing it. My son is 8 months old, and I've tried with him but every time, he gags until he pukes. I only give him any of the top 10 foods to start with like avocado,ripe banana and zucchini, etc. All very soft of course. I cut in 2 inch slices like it says to. I've even tried cutting into very small pieces. Idk how many times it's going to take till he learns how to eat. He even still gags on the melt in your mouth baby crackers sometimes and if I don't control his intake, he just tries to shove everything in his mouth at once before attempting to chew what he already has. I want him to learn cause of all the benefits to baby led but I feel it's hurting him more than anything right now w/all the gagging and puking😔
How do all these other babies do it so well but he can't?? I think about his 1st bday and how he might not be able to eat any of his cake. Did any of you have this problem with your babies and how long did it take them to learn? Will he just figure it out once he's a year old?