Is it wrong to set up a fund raising page for this reason?

Forget the fundraising. You can help your parents but in another way. They have a mortgage endowment policy. This was a mortgage taken out with insurance attached to repay the principal. These mortgages were common at one time and many banks required you to do it that way. However there was no guarantee that the insurance would actually cover the principal repayment and so many people have found themselves in the position your parents are in.

What you need to do is research the details of this mortgage. There is compensation available and it is very likely that they are eligible. Start here https://www.fscs.org.uk/what-we-cover/products/home-finance-including-mortgage-advice/

Read the paperwork they got when they took out the loan. It sounds like they took out an interest-only loan which has a ballon payment at the end, or some other loan where they made lower payments for the 28 years and paid all or mostly all interest, and little or nothing on the principal.. When you say "no one seems to know where that money has gone" it makes no sense - who have you asked? The mortgage company? They should be able to provide a statement. Most likely it went to interest on the balance. What was the original amount of the mortgage, and how much did they pay per month? You can set up a fundraising page if you want to, but don't expect much. You are missing some key details. Unlikely they have been cheated, although they might not have understood their mortgage.

If the bank is demanding full payment of £60,000 after a 30 mortgage it appears they didn't receive it. Your parents should have proof of monthly payments and if they don't they didn't make the payments and I don't understand the bank letting it slide. I don't believe a fund page is warranted and I would not support it.

Yes it is begging.
Of course your parents know where the payments have gone they would have received annual statements every year. Sounds like an interest only mortgage which is coming to the end, and they should have taken out Insurance to cover it when the term ends.
UK

Fund Raising Pages are just high tech begging, no different then the bum on the corner with a tincup

do it!
fundme

Filr a complaint with the banking commissioner in your state. All banks have to answer to them

I seriously doubt any fund raiser would reap any amount of money
you would be wise to search this mortgage and trace it back to the original one
which would appear to be a balloon payment in the final three years, which in of itself seems very odd
go to the company they pay the mortgage to, trace back with that company, possibly the company before them etc, somewhere there has to be legal papers of the original mortgage and its terms
i all else fails sell the house and pay off the note and move on

forget the fundraising... you can help your parents but in another way... they have a mortgage endowment policy... this was a mortgage taken out with insurance attached to repay the principal... these mortgages were common at one time and numerous banks required you to do it that way... however there was no guarantee that the insurance would actually cover the principal repayment and so numerous people have found themselves in the position your parents are in...

Do it!
Fundme

Of course it is OK. It is just that there are so many different people with sad stories on GoFundMe that it is doubtful that you will get much.

I think it's wrong of you to do this without your parents' knowledge and approval.

Other than that, you can beg for whatever you want. It's up to each person who sees it to decide if they want to give or not.

Your parents are grown adults. They have a mortgage contract. They ought to know what they signed and have proper records that show they paid as they were supposed to. If they didn't do that, too damn bad.

If they can't afford the house, they'll need to sell it.