I concur F availability right now is good. And I wouldn't hesitate putting my Avios to work considering the low cancellation fees.
What is more debatable in my mind is whether people should go out of their way to collect extra Avoid at this stage (through promos related to purchases, subscriptions, credit cards etc.) Personally, I think there is less incentive to so.
Ofc, BA likes issueing Avios right now. People have fewer chances to redeem their Avois, hence the issuance of Avios strengthens IAG's liquidity position. Of course, BA won't devalue Avios these days (why mess around with the one business segment that's doing well for them?) But once air travel recovers they will have pretty strong incentives to devalue. Ofc, another downside of hoarding Avios from the perspective of the consumer is that the asset you're accumulating is pretty illiquid at the moment.
tl;dr I think it's a good idea to burn Avios at this time if you can find a way to work around travel restrictions and such. But I don't think building up a stack of Avois today with future F redemptions in mind would be such a good idea.