Why do we buy compost?

Thanks for your replies.
As you may remember I bought a garage load of Coir last year (being sold off in Morries). I thought I'd be able to start seeds in that but its not working for me. Poor germination and those that do germinate are weak. For the first time in living memory I have NO tomato plants.
Currently, I'm mixing the coir 50/50 with a bag of compost which is giving better results but I've lost confidence in the coir. It may end up as top dressing on beds as I don't want to risk sowing seeds, or planting tomatoes in it.

100% coir can be tricky to grow in. It's easy to overwater because the surface dries out quite quickly even though just underneath it's still very wet.

It also doesn't contain much nitrogen, which is probably the most important nutrient for plant growth. Seedlings shouldn't need extra nitrogen until they've reached the true leaf stage, but growing in 100% coir after that point will require frequent fertilising.

My first year gardening properly, I started all my seeds in coir. It dries out so fast that I killed almost everything I started indoors. Probably okay if you have a schedule where you can check fluid status at least twice a day but it did not work for me at all!

Same as TMTT. My clay soil is too heavy and can dry to a brick. I try to reduce my compost use by single sowing in modules and planting out when quite small, with fleece etc. I have also reduced "wasteful" sowings by calculating how many plants I can realistically grow on.
Most of my seeds are started on heat - clay soil drys like a brick. I once used mole hill earth for my chilli plants in pots - OMG! I couldn't believe how heavy they were. Was a complete disaster.

I use the compost in my bins for cuttingshrubs and dahlia tubers that I start in pots. Putting an inch or so of bought compost on top. I try my best to not put weed seeds in my compost but its always riddled with them.

I bought 10 x 60L bags of ericaceous compost from Lidl today for my extended blueberry and cranberry beds and fruit frame. They were €5,99 per bag.
Not opened them yet, hopefully will do that tomorrow evening.

How did everyone do for compost this year?
I didn't buy any and still have stacks of coir and about 3 bags of compost bought 2 years ago.
For the GH tomato pots I used a mix of hotbin compost and some bagged compost. Contrary to the blurb, the Hotbin does not kill all seeds - tomatoes and some sort of squash germinated in the hotbin compost. It takes a lot to kill a tomato seed, unless you want to grow it when it might struggle!
I'm going to collect some molehill soil from the garden and mix it with coir to see if that gives it more body for seed propagation.

I only had 2 bags of compost this year. I used lots of soil from my old veg beds and the contents of all my compost bins. I did buy a bag of compost while I was in civilisation. Mostly for seed sowing. Not started using it yet. Hoping to make enough of my own when I’ve got my garden a little more sorted.

I made all my own this year with coir, soil, perlite, sand, fertiliser, homemade compost, leafmould, etc. I started off being meticulous about the various recipes but after a while just chucked in what was available, reclaimed compost, manure and stuff until it felt right. It was very satisfying stirring up a batch in the wheelbarrow. I can't say I noticed any difference between my own or bought. I might have used a last year's bag of bought for early sowing but not sure. I'm going to miss Wilko for getting coir.

How did everyone do for compost this year?
I didn't buy any and still have stacks of coir and about 3 bags of compost bought 2 years ago.
For the GH tomato pots I used a mix of hotbin compost and some bagged compost. Contrary to the blurb, the Hotbin does not kill all seeds - tomatoes and some sort of squash germinated in the hotbin compost. It takes a lot to kill a tomato seed, unless you want to grow it when it might struggle!
I'm going to collect some molehill soil from the garden and mix it with coir to see if that gives it more body for seed propagation.

I know a bloke who used molehill soil in his raised bed for growing showleeks. When it rained it turned to something similar to concrete!

^^^ That's why I'm planning on mixing it with coir.

Why would molehill soil be any different than ordinary soil, do the moles do something to it? Luckily we've never had moles, voles or badgers to contend with. Rats, pigeons and squirrels, that's another story.