Make better use of the loading screen

[BTCparadigm]

Testing converting.

Discussed in #9750

^{Originally posted by BTCparadigm December 11, 2022}

The animation is cool but it would be more useful to have a slideshow about the basics of the wallet or bitcoin.
Kind of imitating a loading screen of a game.
https://www.youtube.com/watch?v=hhVT7ydgGxo&ab_channel=GamingBolt

[turbolay]

I'm making my statement here as well to have better track of records:
Related: #9076

Something that I think needs to be changed in the loading screen is the estimation.
It's not possible to give a correct estimation because we don't know how many blocks we need to download in the future.
Example: If you made a transaction each block in the 10.000 last blocks, but nothing before, you will be stuck several hours with an estimation showing something like "10s remaining".

A better metric imho would be the current date we're at (ex if we are downloading block 650.000 we show the date of this block). So an user could understand it's longer at the end because well he participated to lot of transactions around this date.

[Transisto]

It's not possible to give a correct estimation

?
It's possible to make a very very accurate estimation because each block has a timestamp and we know what time it is.

[turbolay]

It's possible to make a very very accurate estimation because each block has a timestamp and we know what time it is.

No it's not possible because block downloading is currently done sequentially (keys are derived when a TX is found in a block). To do a precise estimation, we need to know how many blocks we still need to download, which is not information known at this time. This is exactly the isue with the % right now, it doesn't know the total so how a percentage could be accurate?

The software could display the date of the block it is currently downloading or its height as stated with my previous comment along with an estimation if we want, but not only an estimation.

Note
We are currently searching ways to improve the wallet synchronization workflow.
In the future, we might be able to give a better percentage because most of the keys could be tested while block are downloading, see #10014

[nostitos]

What can't Wasabi do with the estimate that core can do?

I don't think the current estimte can be much worst.

[turbolay]

Core downloads all the blocks, so the estimate is quite easy. Wasabi downloads only the blocks it needs, and it doesn't know if block N is needed before being at block N-1, so estimate is impossible

[soosr]

Actually, we could compute it as every block has a filter so from the filter count we could calculate a date. But...
This is something that doesn't align with the principle of Wasabi. We want to avoid technical details as much as possible.
The loading screen should mention the time and how much more the user has to wait until they get to the home screen.
If it is not possible to provide a correct time estimation and it causes more confusion than it helps, it should be just removed.

[MaxHillebrand]

I think @edi21 should take a look at the loading screen in one of his sprints. I'm moving it from the minefield to the UX board so that it's on his radar.