We need to sort out this mess.
The food industry is the worst offender. If I got to the pound shop or the 99p shop or my local newsagent I can buy a 2 litre bottle of milk. If I go to the supermarket I have to have 1.136 litres or 2.272 litres. If I buy tea it's in convenient 125 or 250g packets; coffee comes in 454g packets. Most things are metric, so let's get rid of the anomolies once and for all. While we're at it let's use Joules (or MJ) for energy rather than Calories or kW.hr.
The only two exceptions I'd make in the short term are beer glasses in pubs and glass milk bottles for doorstep deliveries. That's not because I have any objection to drinking a "large" (500ml) or a "small" (300ml) glass of beer, but because I don't want to impose additional costs on publicans and dairies. I'd ban the introduction of new imperial size glasses and bottles except for souvenir shops, home use etc. Wine and spirits are already sold in metric quantities and pubs should switch over for beer when new glasses are needed. Their remaining old glasses can be sold to pubs that wish to remain 'imbeerial' for a bit longer. Something similar could be done for dairies.
The government and the media seem to think metric is fine for engineering, commerce, aggriculture, fisheries, construction, ... but not for the general public who are a completely different set of people that can't cope with all this new-fangled stuff. I was taught metric units in school (cgs not SI) and that was 55 years ago. The excuse that we can't handle metric units is just nonsense. We changed to decimal currency in 1971. Who would seriously want to go back to £sd now?