Since Danny Welbeck went off injured in the draw with Palace, we've drawn with Liverpool, Leicester, Arsenal, Norwich and Newcastle. The only team to beat us in seven weeks before today was Man city. Hardly reason to start panicking.
2 of the five teams you noted got over a quarter of the way through the season without a win. One of them is now a third of the eway through the season without a win. That we couldn't beat them undermines your point a little bit.
Who ? (edit...i looked it up )
In 2018/19 - the wages total was this.
In 2019/20 it was this
Teams with smaller budgets than Albion pretty much er, get relegated and only 1-2 finish ever finish/above/around us.
via http://priceoffootball.com/brighton-2019-20-reel-around-the-fountain/
And this is the fundamental 'problem'*. The top ten target that the club have stated is going to be difficult to achieve when we pay bottom 6 wages. Time and again it has been pointed out that teams will finish roughly in line with wage bill, give or take a couple of places. Leicester's title win was a freak season. We are counting on a freak season like that to achieve a top 10 finish on our wage bill, and will require continued freak seasons to stay there. We fail to beat teams like villa, newcastle, palace, because they pay more, and get a better quality player. So while we pass it around, and slowly plod our way up to the final third then run out of ideas, they have the players who are good enough to retain disciplined, patient shape and the efficiency and ability to take the chances that they get, when they can pressure us, or we lose focus and make mistakes.
I know some of the people who want to believe/hope we can have that freak season will point to the table showing us in 8th, but it isn't the end of the season. Last season we had a great run of three wins in four at the end of January. But look over the rest of the season lots of draws and very occaional wins/losses. We had that purple patch at the start of this season which has given us the impression of having improved further than we actualy have. We will end up in that 15-17 area again because that's how good we are, because that's all we can afford/are willing to pay wages for.
*I say 'problem' because it is a philosophical idea, do I want us to start paying top 10 wages? It's not my money. If the person whose money funds the team wants to limit the outlay, it's not my place to criticise him (I do think it foolish to keep pushing the top 10 dream if you won't fund it). Yes I still get frustrated when we fall short game after game (not enough to finish off winless Newcastle, not enough to actually make Arsenal goalkeeper earn a clean sheet despite such dominance of possessition and territory, etc), but if TB wants the club to run on a certain budget then we should all accept that.
I know there is also this golden dream of an academy where we bring players through, get the benefit of top ten quality players on 'just out the academy' wages, before having to sell them on, but look at Ben White. The best, so far, to come out of the academy and he's sold after one season. Hardly using the academy to get top ten talent before they have proven it and can command those wages.