Vampyr, on 2020-June-12, 17:13, said:
I don’t agree with any of this (in a 5-card major context) where few people will be bidding 2♠ on any hand with 4-card support in an uncontested auction unless the hand is very barren. In competition, as in the hand in question, the reason 2♠ works well is because there is room for opener to make a game try, and she will. I am not a big fan of 2♠, 3♠ or 3♦ on this hand; it was not posted as a problem because it is easy. I play transfers but anyway would most likely bid 3♦, as it is reasonably descriptive.
I would not play 2♠; that leaves me no bid for a hopeless hand with 3♠. If the auction gets very high very soon, the fact that we have a fit will be important for partner to know.
I'd suggest that you read MikeH's response in between yours and this one. We disagree on 2S vs 2NT, but, the process is clearly correct. You have to define bids within the context of available options. 3S is weak and to some extent preemptive. It does not inherently guarantee 4 spades, but, most bids of 3S without 4 spades are insanity, especially vulnerable. Nonetheless, 4 spades is not a requirement, even though it's clearly advisable and this is fundamentally why we won't agree on this.
If you want to say that you play different meanings for 2
♠ and 3
♠ given that you have fit jumps or transfers available, that's absolutely fine, but, it's also a pointless argument. When talking about what's standard, there's no value in bringing in non-standard treatments, even if I do agree they are effective treatments.
If 2S shows 0-9 and 3
♠, 3S shows 0-9 and 4
♠, and 2NT shows all limit raises, well that's a horrible set of agreements. Sounds like a great way to play losing bridge.