I hear you.
To answer your question directly which is the potential issues if he just never eats are:
Weight loss, malnutrition, speech and language delay. If he started to lose weight or develop any concerning symptoms you'd be referred to a paed before it got anywhere near dangerous. This won't happen though unless he had something underlying going on (no idea what. A paediatrician would be able to tell you)
OP, I've worked in HV'ing for a good few years. Lots of children aren't ready for solids at 8 months, it's not at all uncommon. Sometimes it just takes them a bit longer. If the HV is doing a home visit make sure you've told her before hand to bring scales (just incase, if you've only said you want weaning advice she probably won't automatically think to bring scales), so atleast then you can get an up to date weight plotted on his growth chart.
A few random bits of advice that you're probably already doing: Keep offering him 3 meals a day consistently. Even if it's a bit of the toast you're eating, a few bits of pasta off your plate, even if you know he won't touch it, just offer it.
Offer food in between bottle feeds so he's not starving hungry. Almost offer it as an activity rather than a meal.
He doesn't have to be strapped into a high chair if he hates it.
Eat together, when you offer him something, you take a bite too. If you're having lunch, let him sit and watch you eat with the same food infront of him. Model it for him.
He'll do it! He's just not interested at the moment, and that's ok.