Yes you’ll be able to take it up to the gate and then it’ll be taken off you and you’ll get it back with your luggage. And yes that’s the reason a lot of people get the ones that can fit in the overhead lockers, at 6 months if you can use a carrier then great but once they start wanting to crawl and walk then that passport control queue and the wait for luggage is a nightmare without a buggy.
So you can leave any buggy at the plane gate, what happens after depends more on the airport than the airline I’ve found (I’ve flown with Ryanair, emirates and jet2 with my little one). Some airport baggage handlers take the buggies off and leave them at the plane for people to collect, others send them to the carousel. I usually travelled with a sling when she was little to make any long walk without the buggy easier! Btw, after she was 6 months we bought one of the light travel buggies that can fold up and go in the cabin with you. Every airline except Ryanair seem to let you bring them onboard, so with Ryanair flights it’s still the same regardless of the buggy you have!
Do you have a baby carrier? We just took our 6 month old away with easy jet and took the pram right up to the plane but had to wait for baggage reclaim til we got it back, the baby carrier was a life saver for getting off the plane until we could use the pram again, maybe this could be an option for u? X