I know skate shoes were popular in the past. What about something like say climbing approach shoes? Any other things to consider?

Approach shoes work well if they are robust enough – some of lightweight ones have too thin soles. I use 5.10 Guide Tennies as I don’t like how the bike specific ones fit.
For wintet shoes I’m considering using light hiking boots with sole ground smooth or having them resoled with climbing rubber.

Addidas do a trail shoe based on 5-10 don’t they?
Edit https://www.sportsshoes.com/product/adi9090/adidas-terrex-trailcross-sl-shoes-~-aw17/?utm_source=google&utm_medium=price_comparison&utm_campaign=googlebase-uk&gclid=EAIaIQobChMI-vLkmKLr1gIVrr3tCh3AyAtLEAkYECABEgLLdvD_BwE&gclsrc=aw.ds

Whatever cheap Vans are in the end of summer sale. I make two pairs of £20 shoes last a year.

The Five:Tens that started the whole sticky soled flat shoes thing were simply re purposed approach shoes so yes, they ought to work.

Salomon were marketing the XA as bike ready at one point… one of the mags reviewed them

Vans

http://www.bikeradar.com/mtb/gear/category/clothing/shoes/product/review-salomon-xa-pro-3d-ultra-2-shoes-12-46211/

I have Haglofs Vertigo II GT Shoes

Guide tennies. Or cheaper and a bit less sticky are these…

https://www.decathlon.co.uk/arpenaz-500-mens-walking-shoes-khaki-orange-leather-id_8328361.html

The tread pattern works well with pins on flats, but loses grip after a while (year of riding) when it gets cut up.

Grippiest soles ive found are on my hi-tec silver shadow’s.

Simply stunning!

If only the laces didn’t flap around…

I use Adidas Terrex Solos for both trials and on the mtb.

Most of my riding these days seems to be done in whatever’s on my feet or next to the door. I’ve probably only worn bike specific shoes a couple of dozen times this year. I mean I wouldn’t do an MTB ride in sandals, but I did 20-odd road miles in Tevas the other week…. 🙂

Trouble with vans and most skate shoes is they’re dire in the rain. After years I begrudgingly bought some shimano flat shoes (I know they’re not popular but I like them) and they repel most water. Far more comfortable than years with vans, Duffs etc

For winter I’d be tempted with a walking shoe/boot but grip tends to be “chunky” so not sure how good they’d be.

Waterproof socks have really helped!

I see the review, but I’m dubious how good they actually are. I’ve tried various shoes with flat pedals and I didn’t find Salomons great as the sole has too much curve. Fine for pootling, but the shoe pedal interface isn’t all that secure if you’re wanting your feet to stay on.

The question is why not bike specific shoes? I’ve used skate shoes because they’re cheap (at least they can be) and comfy and work well – the only major negative is lack of stiffness, but for messing around they work great. I’ve also used off-road running shoes for when I want better grip for hike-a-ride – I’ve not found any which work as well as specialist shoes, but those with a wide, flattish forefoot work fairly well. Haven’t tried approach shoes, but I expect they would work well. It’s a compromise between grip for walking and grip on the pedal. Though last year I walked to the top of Snowdon in my riding shoes having ridden up the miners track (I hadn’t planned on going to the top when I set off!)