There's really no problem with how things are right now.
Some LOs take to solids in a big way from a young age, others aren't really into solids until they are a bit older and either is totally fine.
Is he comfortable enough in the high chair? Is it upright? Can you help support him with a rolled up towel behind him for instance?
All his needs are met by his milk, there is no hurry to gain nutrition/calories from solids. By 11-12 months you'd expect to see him joining in with regular family meals and a balance of milk and solids, likely a snack or two in additional to 3 meals. By 12 months you'd expect LO to be getting most of his nutrition/calories from solids, but he'll still need milk and will continue to do so (usually at WU and BT but that isn't a rule). from 12 months milk can be cows milk, it's your choice if you continue to BF, or give formula, or cows milk.
There are a lot of changes between 7 and 12 months, it sounds short to us adults but it is along time for babies. Just because he will be expected to have regular meals at 12 months doesn’t mean it needs to happen right now, he may have more interest at 9 or 10 months for instance.
Many people don't mind LO sitting on their knee for solids. Personally I only did this very few times as I wanted my hands free to eat my own meal!
Sounds like he is doing totally fine munching away on meat and broccoli, keep offering but don't force him, and he will be getting great experiences of these tastes and textures. By the way, he doesn't need any teeth to manage just about any food, their gums are very capable.
