OK, first up. It never once occurred to me to occupy my children's every waking moment with parks, playgrounds, interaction and whatever. It doesn't matter if a kid is 'easily bored' - and any child would learn to be 'bored' if they were given constant entertainment on tap. Kids being bored is a good thing. It means they get their toys out, they play creatively, they use their imagination. They draw something. Try to resist the initial 5 minutes of whinging. He needs to be bored. He needs to learn to entertain himself and, more importantly, you have things you need to do for yourself. You can't spend all day catering to his whims. I had a tidy house when I had toddlers because it made me much happier to clean than endlessly play. And they play well independently. Win win.
Right. Next, many adults are frankly not natural players. I'm not. I really struggle, even though I'm nearly a decade into this parenting thing, to find any fun at all in children's activities. I do not craft. I do not get excited by pony rides or clowns or balloons. I cannot sit on a floor and do imaginary play for hours. And there is nothing wrong with this. The children play and they are happy. I interact a little but, mostly, the game is for them to learn and enjoy, not me.
Your DH has plenty of other ways to show his affection for his son that don't involve crawling on the floor making noises with cars. He might prefer an adult conversation - and so might you!
OK, yes, he shouldn't 'ignore you all'. If he wants to watch a specific show then fine (actually, no, watch it later when the kid's in bed), but I am not one who likes TV on as 'background noise' or just put on for the sake of it. He can come home aaaaand find something useful to do, like help with meal prep, he can come home and hang/fold laundry while the child watches and 'helps' (talking while doing chores is as educational as any game), he can simply ask you if there's anything you'd like him to do.
I won't go as far as to say he MUST get down and do floor play, because honestly, it's hard, it's dull, it's not fun and if someone tried to make me do it after a day's work I'd throw something at them. Kids play with toys and I'm done pretending I do too.
But yes, there's other things he can do that are not vegging out in front of trashy afternoon non-TV. Honestly, just reconnecting with you might be a better use of the time than toys.