Yes, it's completely different to the 70s/80s when there was more of a ladder but it was a very slippery one!
Some figures to demo:
In 1970, avg house price was 5k, avg salary 1.8k
In 1975, avg house price 10k, avg salary 3.8k
In 1980, avg house price 24k, avg salary 7.6k
So if you bought your house in 1970, inflation meant that by 1975, your 5k mortgage had depreciated in real terms to a much smaller debt. Your debt stayed at 1970 levels but you now had a much bigger salary. By 1980, that debt had depreciated again and was easily less than a year's salary. The debt soon becomes dwarfed by your income, which means you can borrow more. Of course, the high interest rates that went along with the high inflation meant the mortgages were much MUCH harder to service than they were now, but for those who could continue to pay the interest, inflation drove their debts down to almost negligible. In 1980, if you still owned that house, you were paying off a debt of 5k, on a salary of 7.6k pa, and even at 15% that was often manageable. Whereas these days our debts are easier to manage because of the low interest rates, but they stay significant big lumps longer than my parents' first (several) mortgages did.
Also, the high inflation must have been a huge push to buy. In 1980, it made sense to push onto the housing ladder asap because if you waited 12 months, you'd have to pay 15% more for the same house. Rent, and your rent will climb year on year in line with your salary increases (ish). Buy, and your salary continues to rise while your debt doesn't. The same goes for anyone wanting to move up the ladder. It made sense to push yourself to borrow as much as possible, because high inflation meant it would soon come towards you. As long as you could keep paying those high interest rates - and not everyone could.
I'm 40 and we see it among our friends. Some bought for 70k straight out of uni, others for 200k 3 years later. What enabled those early buyers to move up the ladder was not huge chunks of equity per se, but the smallness of their existing mortgage (though I'm sure 70k felt huge at the time, and compared with their parents' 5k mortgages it was.) They could borrow an extra 100k to move up the ladder, whereas later buying friends were stuck servicing much bigger mortgages and couldn't. So OP think of yourself as the 70k mortgage holder rather than the 200k one. Your monthly payments are a good bit lower than they'd be if you had a 300k mortgage, you're better protected against negative equity, you are much more able to borrow more, because you're less risky to banks but more importantly because your mortgage is less per month, you may be living in a lovely home you wouldn't have otherwise afforded because you couldn't stretch to the full 300k at all. This is all very positive, and it's because your debt is relatively smaller rather than because the number of GBP of equity you have IYSWIM. Or that's my interpretation anyway.