Personally I feel the DLC was less scummy than an extremely extraneous third version like USUM. I'll take paying half the price of a Pokemon game for two expansive areas and their own quests over spending the price of a new game for essentially the same game over again with a few extra things. I never felt cheated about the SwSh DLC but USUM felt so unnecessary I couldn't bring myself to finish them.
SM base price at launch (40 USD) + USUM base price at launch (40 USD) = 80 USD
SwSh base price at launch (60 USD) + SwSh DLC base price (30 USD) = 90 USD
There was also an option to purchase SwSh with the DLC pre-installed, but I don't know how much that package deal cost. Though, knowing Nintendo, I lean towards it just being the full price.
But, that's not all. Ignoring the hardware cost difference, there's also the additional costs associated with reaching feature parity for WiFi. The Switch's online service costs 20 USD per year. This price can theoretically be distributed across the number of games the player actively plays, but it will never beat the 3DS' wifi cost. Which, you know, is still zero.
Not only that, but GTS access was removed from SwSh and remanded to the Home software - but not the Switch program, mind you, but exclusively the mobile version. Which means you'll need to download and keep a separate program on your mobile device if you want GTS access. Not to mention Home "Premium" itself is three times the price of Bank, just to add features that were already in the base game for Gen 6-7 - though I won't add it to the overall calculation since it is "technically" optional (unless you're one of our illustrious Smogon WiFi hoarders :P).
In terms of content, USUM/SwSh DLC do about the same. Brings back move tutors? Check. New Pokemon? Check (New UBs/New Legendaries). More gameplay? Check (Rainbow Rocket + Ultra Wormhole Legendaries + Mantine Surfing/whatever the SwSh DLC has). More gimmicks? Check (New Z moves/New Gigantamax forms). They both add more or less the same things, with minor variations. The main difference is that USUM has mostly the same SM gameplay loop to play/replay, while the SwSh DLC has two-three hours of story to complete.
I do agree that, with the probable exception of BW2, the "improved" version of each base Gen title was/is incredibly scummy. They're an obvious attempt to milk customers for additional money with minimal effort. But the SwSh's monetization practices are ethically no better, and cost far more than past-Gen's. The price + hike + minimal content change is just masked better, that's all.
To bring this back around to Gen 9, we all know GF/TPC/Nintendo won't stop with the extra monetization. It makes them too much money, and there's zero incentive for them to stop. But, hopefully they won't make it any worse (such as microtransactions for cosmetics/items), and maybe if we're lucky we can get the GTS rolled back into the base game?