上来 and 上去 are not about up. They are about where you stand

Where the picture shows up in 上来/上去

1. 1

   up to where I am

   电梯坏了，你走楼梯上来吧。

   diàntī huài le, nǐ zǒu lóutī shàng lái ba

   The lift is broken, come up the stairs.

2. 2

   up away from me

   我马上上去拿。

   wǒ mǎshàng shàng qù ná

   I'll go up and get it right now.

3. 3

   carried up to me

   麻烦你把这箱水搬上来。

   máfan nǐ bǎ zhè xiāng shuǐ bān shàng lái

   Could you bring this case of water up, please?

4. 4

   up onto a surface

   名字写上去就行了。

   míngzi xiě shàng qù jiù xíng le

   Just write your name on it.

   Here 上 is not a floor but a surface. Landing on a page counts as 上 too.

5. 5

   up out of your head

   你问我为什么，我一时说不上来。

   nǐ wèn wǒ wèishénme, wǒ yìshí shuō bu shàng lái

   You ask me why, and nothing comes to me right now.