Yes absolutely worth it - long term, subject to a couple of caveats.
Driver was schools - moved to an area with some of best state schools in the country. Absolute no-brainer for us, children v happy through school, on track to get top grades etc.
Caveats -
We were already in the childcare years so knew income would increase over time as soon as we stopped / reduced child care costs.
It was a long term house so knew we wouldn't be looking to move again any time soon.
We spent years not being able to afford to do anthing to the house (lived with no carpet in hall / on stairs for a year or more, 60s bathroom, couldn't really afford anything other than paint). Thats tricky and demoralising at times - you've got to be on board with that. Also meant nothing fancy re holidays / cars for a few years forever.
We've extended it / remodelled now so it is largely what we want. With the way prices have increased over recent years, had we not taken the leap when we did, we wouldn't be able to afford it now.
Should also say we were relatively lucky in that mortgage rates were quite good / not rising for the period we were massively stretched. We've just had to remortgage and even though we don't have a big mortgage, the rate has jumped so much that our repayments have gone up by £400 a month. That would have been a disaster had it happened when we'd just bought this house, so as a pp has advised, if you do take the risk, fix your payments so you've not faced with unexpected jumps.