”Tricks and loopholes” are exactly how certain high-value exemptions and reliefs can or could easily be (mis)used, primarily by people with enough surplus wealth that they can afford to lock up in illiquid or somewhat riskier assets.
Some examples:
(1) farmland exemption from IHT, designed to allow family farms to get passed down the generations, get used by people with lots of financial wealth who have never farmed: they buy farmland, driving up land prices, which actually makes it harder for farmers to buy land and allows non-farmers to avoid IHT. This loophole is not available for normal middle class people trying to save for their future because farmland comes in larger chunks and is illiquid.
(2) VCTs, designed to allow investment into risky startup businesses, can actually contain lots of mature businesses paying reliable dividends. Wealthy people can buy them in order to get an immediate income tax cut and a future exemption from tax on dividends and capital gains. This may be available to normal middle class people if they are comfortable with the investment complexity.
(3) to avoid CGT altogether, a wealthy investor can borrow against their portfolio to fund current spending instead of selling assets and paying CGT. As the portfolio grows, so does the available borrowing. This works especially well for people who have way more than they need because they avoid the risk of margin calls.
(4) Pensions used to be touted as a way for people with plenty of non-pension money to sock away money for heirs tax-free in the event of an untimely death: there was an income tax break upon contribution on the way in, no income tax due on the way out, and no IHT. People who needed that pension money later in life to fund retirement would pay income tax on the way out, but people who did not need it could use this as an extra nil-rate band.
I have seen numerous promotions each all of the above approaches to saving on tax, which are of most benefit to the top 0.1%. For examples a VCT investment can offer a £60,000 income tax saving every year, plus tax free dividends and capital gains on the £200,000 investment, to a any person with enough surplus income or capital to invest that amount every year. The pension loophole allowed a wealthy individual to get an extra £1 million nil-rate band for their heirs and to fund it using pretax money.
Maxing out ISAs, thoughtful use of pension relief, and home ownership can together provide a very healthy dose of tax relief for anyone in the bottom 99% of earners in the UK and can probably allow most people to do most or all of their saving in in a tax-advantaged way. If we were to keep consistent policies on ISAs, pension allowances, and PPR on owner-occupied homes, and eliminate all of the reliefs I described above, it would really only affect the top 0.1% of taxpayers.