But it does create a massive tax loophole: because I'm a software developer, I can deduct the costs of any computer I buy, but nobody is checking whether I actually use it for work or for gaming. I can deduct work lunches, but employees can't. I know someone who deducted his motorbike because he also used it for work. I can deduct phone and internet costs because I also use them for work.
I find the way I can avoid some taxes that others can't, rather questionable. Frankly, everybody should have their own company to avoid this inequality. And the stuff I can deduct is small potatoes compared to the stuff I'm sure some other people are deducting. I'm no tax expert, but I'm sure this is a big part of why billionaires pay so little tax.
Also, companies on the edge of the health care system have a problem, because health care is VAT free, so health care companies cannot get the VAT back they have to pay to their suppliers, which makes suppliers of services to the healthcare industry effectively more expensive than they should be. I think this whole system is in dire need of an overhaul.
And I'm certainly not going to look up tax laws; that's exactly what I'm paying my accountant for.
Your accountant keeps bringing deductions up because he wants you to feel he's worth his fees. That's why literally every accountant I've ever worked with has told me that "a good accountant pays for himself". Accountants compete with each other based on how much they can lower your tax bill. So yes, of course they'll help you make unlawful tax deductions, and they'll reassure you that it's perfectly fine and that they have many years of experience etc etc.