Export all the owned steam games titles to an Excel/ text file?

Not that I really know of (not very helpful I know), but for keeping track of all games in all platforms libraries (GOG,Steam, EGS, amazon, etc.) I recommend playnite has worked for me for awhile.

according to chatgpt: There are Python scripts or apps like SteamGridDB Manager or Depressurizer that can export your Steam library as a CSV file.

Let's see if I can tell you the steps without mistakes:

Go to Steamdb.info
At the top, choose Calculator.
Enter your profile URL or SteamID, then click "get disappointed".
At the bottom left there's a menu. Click "Games" just below "Information". NOT the one under Steam Links. Above.
Now you're seeing a paged list of all your games, 100 games per page by default.
Just under "Owned games" you can choose how many games per page. Choose "All (slow)" and wait for the page to be generated.

Now, if you only want to have the names, keep the control+shift keys pressed, click in the first name cell space (not in the name itself, it's a link), and then move the mouse down to the next cell. In Firefox that selects all cells in a column. You can release the keys and now Control+C to copy, and paste in your fav text editor, in Excel, wherever.

If you want to have more intormation, right click anywhere clear, and choose "see source code". Copy all and paste in a good text editor (I use Notepad++ but there are plenty of good free multipurpose full-featured text editors). Now it's a matter of getting rid of what's on the header and the bottom and keep the code of the list. With some smart substitutions and including tabs, you'll end with a tab separated list of appIDs, names, prices, time spent, rating... Import/paste into a spreadsheet and play with it.

This is what a single row looks in HTML so you know what you'll face, it will not be hard to get it sorted out:

<tr class="app" data-appid="2092750" data-capsule="capsule_231x87.jpg?t=1729930228">
<td></td>
<td class="applogo">
<a href="/app/2092750/" tabindex="-1" aria-hidden="true">
<img src="/static/img/applogo.svg" alt="">
</a>
</td>
<td class="text-left">
<a href="/app/2092750/">Tina &amp; Rook! Cookie Quest!</a>
</td>

<td class="muted i" data-sort="-1">-</td>

<td class="i muted" data-sort="0">Free</td>

<td data-sort="6">6m</td>

<td>86.69%</td>

</tr>

What you should try...

Playnite with the HTML Exporter add-on is doing an extraordinary good job at that !

Even with default settings, what you get is a full-featured grid-view with images linking to the full descriptions of the games. Everything is sortable and there's even a built-in search engine. (You can have it as text list also with another built-in template)