Years ago I thought that but I learned that when the police replace tyres they put the new ones on the rear and part-worn to the front. So I looked into it and found out why.
Basically, you're more likely to lose grip on the worn tyres and you're far less likely to catch a tail skid in front-wheel drive car than a front wheel skid.
Some years later I found this to be true myself. My wife got me a skid pan session for my birthday. One of the activities was driving in a circle and getting faster and faster until the car skidded. Two cars were used for this, one with bald front tyres and one with bald rear tyres. I couldn't get the car with bald front tyres to skid because as soon as I felt the grip start to go I automatically backed off and caught it. The guy was telling me to keep pushing until the car skidded out but I couldn't overcome my automatic instinct to catch it.
By contrast, I couldn't catch the rear-wheel skid. Not one time. As soon as the back started to go..whoosh, it was away.
Personally, I wouldn't put two tyres with widely different grip levels on my car. That could go very wrong. Of course you could drive around like that until the old tyres are worn down without anything happening but if you had to brake hard on a wet or icy road bad things could happen.
It is amazing how many people think they can drive quickly and catch slides, but don't take professional instruction yet put everyone at risk by practicing their skills on public roads.
Years ago from when I was 17-18 I was like that, I used to time myself on journeys and try to beat the time. I was lucky that I didn't kill either myself or some other unlucky road user.
Then an older friend got me to join a motor club and introduced me to road rallying. Then I bought a 970cc Mini Cooper S and with sponsorship from a local engineering company who used to replace blown Triumph V8's with Rover ones in Triumph Stags, started stage rallying.
I quickly learned that I was not as quick as I thought I was and after a couple of years had to give it up as it way too expensive for me to continue as the car became less competitive. It did however remove the desire to drive dangerously on public roads.
I learnt a lot about car control in a relatively safe environment (the club used to hire the Army's tank ranges at Aldershot, Hampshire to practice on).
Since then over the years I have taken the courses listed above, plus a skid control course at Thruxton circuit (where I set the fastest time by over 5 seconds to my nearest rival in a front wheel drive car around a short slippery course - the instructor/observer was amazed but I didn't tell him I was left foot braking, I'm sure he wouldn't have approved!). Nevertheless left foot braking is a real "get out of jail free" card in a front wheel drive car in slippery conditions, but sadly most cars made in the last 15 years won't let you do it, as the computers sense you have both brake and accelerator pressed at the same time and cut the power.
Even after over 50 years of driving I'm still learning things, and doing high performance driving courses teaches you so much about car control, road positioning, observance and of course yourself.
