What's the point of blockading?

[Hermerico]

Trade power hit from blockade at 100% seems awkward, since it wouldn't block river or land trade. Thus we'd expect devastating impact on trade, but not 100%

On the flip side, it would also indirectly impact far more than just trade, production for example (most often than not you would be importing the raw materials) and weapons and amunition too (non-existing concepts in the game)

 

[grandadmiralbob]

It rarely feels like it does anything to economically hurt enemy nations. I have invested into both naval and maritime ideas and have the policies that increase the blockade efficiency but i don't feel it really does anything terribly much at all. Shouldn't it increase the war exhaustion of the targeted nation? And make trade for them harder overseas?

It's situational, but the best time to do it, is when Ming is having their disaster. Free money, and if you're playing as Bruneii, you don't have anything to worry about at all, not even call for peace.
As for it's broad use, it causes devastation, takes their money, gives WE, and it gives your bored navy something to do other than protect trade.

 

[TheMeInTeam]

Not to mention that it was extremely difficult for sailing ships to bombard coastal targets. Steamships can precisely control where they’re going in a way that sailing ships cannot.

Agreed on that, but also:

• Wait, the ships have cannons loaded onto them? Can we haul these off the ships and barrage inland?
• What happened to all of the pre-cannon breaching techniques? We can't break out the shovels with cover fire from besieging forces any longer? No under-mining the structure?
• Did we forget how to create and place ladders for assaults? We knew how to do it earlier in EU 4 patches. It was used in Roman times and before. I don't think it became a lost art!
• No trebuchets to at least give defender penalties? Only the largest of these breached walls, but lobbing stones into battlements was still deemed worth doing with frequency, presumably for a reason. It was also costly, so giving a button to use pre-cannon arty to apply penalties and/or allow (more costly) assaults seems reasonable compared to just starving out forts, which given how long they take in EU 4 seems to be the default approach.

On the flip side, it would also indirectly impact far more than just trade, production for example (most often than not you would be importing the raw materials) and weapons and amunition too (non-existing concepts in the game)

True, but we're not in Vicky where econ side is modeled to this extent. Having blockades equally impact nations like Mali, France, Aztec, and Kilwa would be bonkers. A full fledged period blockade would impact all of these, but to massively different degrees. Azted would be intimidated and lose a little trade, but the majority of its economy would remain intact. France would feel it very significantly, assuming you could blockade it in both Med and Atlantic. Depending on exactly when we're talking about, Kilwa would be screwed. Mali would be somewhere in between; more impacted than Aztec, but way less than the others.

Long-term econ damage to target is also simply a bad "incentive" for war in EU 4 right now. I don't care how many players post pictures of their kobold attrition strat hell wars that take 8 years to get 40-50% score. That's not how you grow at a decent pace in this game, and that's not what a good war looks like. It's a last resort. If you want to incentivize players emphasizing navy:

1. Dump the atrocious conditional access nonsense, so that diplomacy and mobility mean more
2. Introduce penalty modifiers to blockaded nations' troops. You can say this is an abstraction for procuring enough materials for armies or w/e. Make it irrelevant for "primitives" and scale with trade income from coastal nodes blockaded as a % of target nation's income or something.
3. If that isn't enough, give move speed bonus to allied troops on coastline/penalty for enemy troops on blockaded coast, again relatively easy abstractions to justify (moving in sight of ships = communication about where army is and more harassment, or for friendlies an easier time moving stuff).