I wouldn't worry too much about it. As the others have said, at this stage, solids are more about the experience than the nutritional value. Squashing vegetables between your fingers and drawing on the table with them seems to be lots of fun. I would often give DD one thing to play with and while she was distracted, I would shovel food into her mouth
Just don't let things like cereal dry on the table - it turns into concrete. I've learned that the hard way

It is true that it often takes them a while to "like" a new tatse. And they have a natural tendency for sweet things as breast milk is sweet. So it's not something you are doing to him. DD now has a habit of putting things inot her bowl. So if there's some pasta still on the table from her mains, but I've already brought out the yoghurt for dessert, she decides to have tuna vanilla yoghurt pasta. I don't care, as long as she eats it.

I think you're doing a great job at offering variety for him to sample. But I wouldn't "force" him to eat it as you don't want anxiety to build up around meal times. That would create even more fussiness. I agree with Liz, I do the "ok, this is what is for dinner, take it or leave it". My mum did that with us while growing up. My brother was a little fussy as a toddler. But she would say: "Alright, if you don't like the lamb, that's fine, you can just eat the potatoes" so she wouldn't let him go hungry, but she also wouldn't indulge his fussiness. Not getting attention for it quickly put a stop to it and both my brother and I eat pretty much everything these days.

I found with DD that she was much happier eating a "meal" rather than individual veges IYKWIM. For example she was happy to eat minestrone with all the veges mashed up in it, but she would not like mashed up potato by itself. I guess she's like me, she likes a bit of flavour.
I know the common advice is to introduce foods by themselves and see if there is a reaction. But I decided to ignore that advice and just offered DD what we had in a more mushy form.
So, if we had tuna penne for dinner, I would cook some risoni for her and serve them with the same sauce. If we had Thai Green Curry Chicken with rice, I would give her the same just with extra coconut cream and more rice to dull the spicyness. If we had Cottage Pie, I would feed her the mash, mince and gravy from my plate.
As someone else said, they loooove to eat what you eat.

I also found that DD would eat more and with more pleasure if we all sat down to eat together. So I tried to have dinner ready the minute DH came home so that we could all eat together. We don't always manage to do that, but we try to do that a few times a week. it's a nice habit to get into as a family. But it can also get a little stressful in the afternoons when you have to get it all ready. Pre-cooking really helps here.

All the best, Saša