The basic problem is that the reporting and accounting rules are double plus bureaucratic and you need to have on hand multiple registers that show the financial situation at any time, submit them to the tax authority etc.
To give you a small taste: you need to issue an electronic invoice for each unique customer, and submit on the fly the tax authority - but these need to correlated monthly with the money in your business bank account. The paid invoices don't just go into your bank account, they are disbursed from time to time by the payment processor, on random dates that don't sync with the accounting month, so at end of month you have to have correlate precisely what invoice is paid or not. But wait, the card processor won't just send you the money in a lump sum, it will deduct from each payment some random fee that is determined by their internal formula, then, at the end of each month, add all those deducted fees (even for payments that have not been paid to you) and issue another invoice to you, which you need to account for in you books as being partially paid each month (from the fees deducted from payments already disbursed). You also have other payment channels, each with their fees etc. So I need to balance this whole overlapping intervals mess with all sort of edge cases, chargebacks and manual interventions I refuse to think about again.
This is one example, but there are also issues with wages and their taxation, random tax law changes in the middle of the month etc. The accountant can of course solve all this for you, but once you go a few hundred invoices per month (if you sell relatively cheap services) you are considered a "medium" business, so instead of paying for basic accounting services less than 100€ per month (have the certified accountant look over your books and sign them, as required by law), you will need more expensive packages which definitely add up to thousands in a few months.
Go be an entrepreneur, they said.