Should we both be encouraging DS to amuse himself for a little while?

[teaforall]

DS1(8) has 2 modes: outside being active, or "I've got nothing to do!" Has a Switch but it's limited. Doesn't like reading or drawing anymore. Like DH who is always on the go. DS2 (6) can amuse himself.

DH works FT at home. In school hols whilst he is not working, he is at their beck and call for play. If when I'm on my own with DS1 whilst DH is working and I say we've played but I have jobs to do, find something to do, he cries and stomps. This is after being taken to an activity or played with. I push through and after moaning for 20 mins, he will begrudgingly find something to do.
I am torn:

1. At least DH is playing with him. If DH is happy to be with him, then why is it a problem that he likes having someone with him? They only want to play with us for a short time!
2. It's not about DH playing with him, which is nice is of course, it's about his lack of self sufficiency. There are times when you're an adult and you have to think for yourself and be alone. I don't think after all the nice things we do together, 10 mins entertaining himself is too much to ask. I can't remember the last time DH told him to play whilst Daddy is busy.
3. Some kids are just like this.

AIBU? Should we both be encouraging him to amuse himself for a while? Should I be the only one putting up with the strops?

Not sure how to vote, but my fall back when one of my dc "had nothing to do" was always offering them jobs that needed doing.
"Well, you can wash up / help me change the beds / tidy your room / wash the car / help me with this weeding / peel some spuds / get the washing out the machine / etc., etc"

They generally worked out that entertaining themselves with a ball or some lego or whatever was a better choice (for them).

I say that but he only hears me say that.

I'm only needing him to do this 10/20 mins here and there.

I get that not every child likes playing alone but he totally relies on DH or the TV for entertainment. He used to have reading/drawing as quiet hobbies but he says he doesn't like those now.

He is very lucky that DH does absolutely loads to entertain him yet he’s still saying he’s bored. I think we can’t possibly entertain him 24/7, nor should we. DH wonders why he is shattered at the end of the day!

Start with small amounts of time that he needs to occupy himself in his bedroom without tech (give him a clock or timer if need be) and build up.

Same thing here op! I would encourage solo play by building up to it. Eg start the play together, Lego or something, then gradually retreat, saying ‘I just have to do x’ then come back after 5 mins. Gradually increase. I hope that helps.

I encourage my 3 year old to play on his own and amuse himself as I did with my older children, so YANBU, he should be able to entertain himself. I've never been afraid of my children being 'bored', it's not my job to provide entertainment 24/7. Boredom can lead to great creativity, it's been scientifically proven.