Playing tall can still work well. I personally enjoy playing Sweden tall, so it feels like I'm a smaller nation beating up a larger one, like Sweden did historically despite it's much smaller population compared to their neighbours.
The onlys issue with playing tall are:
Development Cost vs Coring Cost. Per Monarch Point you spend, coring is cheaper for the development you get. You can stack a lot of dev cost modifiers, yes. But it becomes more and more inefficient. Plus Coring Cost modifiers pull that even further ahead.
Trade Power. Yes you can develop, and it will bring you more trade power. But there's still other nations in the node you're getting power in. It's better overall to own it all, instead of owning 80% of the trade power with 60% of the land there.
Trade Goods- Manufactories. Blobbing makes it easier to get things like Leading Producer and the "Trading In" bonuses. And on top of that, there's manufactories. You can build one of every province which equates to 5 Production Development. The more provinces, the more you can build. This in turn increases trade substantially, making you even richer, especially if you blob fully into trade nodes. In friendly MP games my friends and I divide land by trade node, and refuse to pick nations who will get in each others way. Because blobbing works best for trade.
Making Power for yourself- taking it away from others. This one is fairly obvious. You take the land. Someone else doesn't have it. Why White peace a guy and let him keep 40 development? That's 40 you could take away, that's 40 for you. Plain and simple. Blobbing makes you stronger, weakens other nations, or blocks their path.
Blobbing is better, in almost every single way, hands down.
Playing tall is still viable- but definitely less efficient in the long run. It's something I do for my own personal satisfaction- it's nice slapping down bigger nations like they aren't shit when they're physically 8x your size.