The glasgow museum has lenses, I'm sure an optician would too. But do the kids who go to the museum get to use them? Get to take measurements?
I don't want to labour the point here. I realise that you can get round aspects of this, but the bottom line is it is a down side. However much you don't want HE to have any down sides other than less money and a messy house
A dad isn't going to take his kids into work to use the fume cupboards on a bi weekly basis, week in week out. I've got them in the lab! I've also got 3 techs who help maintain and set up all this stuff for me. It massively enriches the learning experience for the kids.
My dd has some great electric kits, which she uses at home. I know that what I have in school is better.
And science isn't the only think. In the school I work in, which is a slightly above average comp we have the following. playing fields and a gym, with a full size climbing wall, the ability for basket ball courts, badminton, and a full size trampoline,.
We have fully equipped metal work and wood work rooms, a brand new cookery and needlework block that does all sorts of interesting stuff.
An art department, with a fully kitted out darkroom (we offer photography GCSE). We have drama workshops and a stage. (school across the road also a comp has a real professional theater and a swimming pool, much to the envy of our kids)
We have a music department with the usual instruments and practice rooms, but we also have (and I shit you not) a real recording studio, with a full small mixing desk.
We also have all the language lab facilities.
The kids have access to some amazing things.
You can do these things via HE, but you'd probably be going some to do them all.