I'm an accountant so see it from the taxpayer's perspective.
The REAL problem is all the tax cliff edges, stupidly high marginal tax rates, etc which impact on behaviour.
The rates themselves are fine, it's the fact that the graph of marginal tax rates at each income level is like a mountain range whereas a sensible coherent tax system would have it as a gently upward sloping curve.
So many income levels where earning an extra pound can actually leave you worse off, or only marginally better off, making it not worthwhile. Hence those earning over £100k shovelling into pension schemes, reducing their working hours etc., to get taxable income back under £100k thus exacerbating shortages in terms of doctors and doctors etc among other professionals too. Likewise a sole trader business may decided to do less work, or open fewer hours, etc to keep their turnover below the £90k VAT registration threshold (turnover NOT profit!!).
I have loads of clients who muddle on quite nicely, paying taxes as they fall due, not doing anything particularly out of the ordinary in the way of tax planning, etc., but suddenly they hit a cliff edge and that's when they start undertaking tax planning and usually end up paying less tax due to the changes they've made (legally I hasten to add!).
Reeve's stupid IHT changes are a classic case in point. I've never been so busy. So many clients with relatively "modest" IHT liabilities or no IHT liability at all, suddenly potentially brought into huge IHT bills, whether due to the moronic pension changes or the stupid changes to business relief. Those who were "happy" for their estates to pay a few tens of thousands of IHT and weren't wanting to do any tax planning, suddenly saw their estates potentially liable for hundreds of thousands of IHT, have taken planning action, and now HMRC will get nothing! Reeves IHT changes will end up reducing the tax raised from IHT instead of increasing it.
Another case in point due to the VAT threshold not being raised. A small B&B in a seaside resort. Turnover being held back under £90k because going over it, even by a single pound, means them several thousand pounds worse off - they'd need to grow turnover to over £105k to "break even" and be back earning the same profit as at £90k. Today, they have two rooms deliberately left unoccupied with "no rooms" sign on the front window - if they let out those rooms this weekend, they'd breach the threshold - the extra couple of hundred pounds would cost them around £10k! Utterly, utterly stupid to have that kind of brakes holding small businesses back. Similarly, another client is a small pie/sandwich shop who only open 3 days per week because that gives the £89k turnover - they can (and would) open another couple of days, but the extra turnover, again, would cost them more than the profit made due to the VAT on ALL turnover, plus costs of power, staff wages etc. Multiply it by thousands of small businesses all over the country and you can see the loss to the economy and treasury, whilst the Treasury mandarins think they're clever keeping the VAT threshold unchanged and believing "fiscal drag" will bring in more tax revenue - the reality is the opposite!