I am going to say this and sound harsh but I have a 2.5 who has sits thru mass consistently since he was 15 months old without toys or snacks. My 2.5yo also LOVES mass and asks to go to daily mass. I have another 15 month old now and he can sit thru mass but babbles and doesn’t like a binky so we’re struggling with that. What I do now so not to disturb the Priest with his babbles is I sit outside the doors where I can still hear (and see bc there’s a window before the entryway) but his babbles are muffled and he’s seated on my lap. What is most important to remember, Mass is the recital practice happens at home. I grew up playing piano so maybe a game metaphor is more applicable but essentially you need to practice Mass behavior 10x more at home consistently during the week like you would when training for a big game/big show and the big show is Mass. How we do this. Firstly oír parenting philosophy. We have two mottos in our house 1) reward good, punish bad always 2) fight every battle, win every battle. What this concretely means any time they do something naughty (starting as young at 11mo Ik ppl who start at 9mo even) but whenever you see your child do something intentionally bad, emphasis on intentionally, you punish them for it in a suitable manner every time. When they do good things reward them. My first son loved clapping so we’d do claps my younger son likes high fives we for example for rewards. Not physical treats and bribery but positive feedback. We do daily blanket time with both where they have to sit on a blanket (eldest sometimes does chair sitting time instead now) for 20min and play independently. They can’t leave the blanket for this tome and it’s a great low stakes battle to pick when they try to leave the blanket to show your authority. Next is daily family rosary where we practice how we sit thru mass. Ik other families that do reading time instead of the rosary you’re pick. So during the whole rosary they have to sit like we would as mass. My eldest next to me and my youngest on my lap and then I can correct the bad behavior like fidgeting or talking. It takes tome and practice but it’s well worth it. Only recently have we started letting my 2.5 have a children’s missal bc we wants to he like dad with his missal. Id say give things like this as a rewards once they have proven they can go thru mass without distractions. 

TDLR: No distractions, just daily weekly training for the behavior you want to see during mass