In summary
Yes notion is a simple way to create your portfolio
There are event templates that you can easily duplicate
My two cents
Someone asked me: Do you think that the Service Design portfolio can look good, when it's made with Notion instead of a proper website?
Yes, obviously.
Because the form of the portfolio doesn't matter so much for Service Design work than it does for graphic design or UI work.
In fact Service Design portfolios are more about the content than the visuals.
And when I say content, it means, understanding what the project was like, understanding what the challenges were, understanding what you learned from it and seeing how you used the methods.
So, if you want to create a Service Design portfolio and you like working in Notion sure, make one in Notion. But if you like other tools, just build it in other tools, it can just be a good old PDF. It doesn't matter so much. What matters is that your portfolio shows what really happened in the project instead of being something beautiful without much content.
Going further
Start with a notion template
There are already plenty of portfolio templates for Notion (both paid and free) that you can use as a starting point.
Step by step tutorial to build your portfolio in Notion
Aliena Cai has created a 16 minutes tutorial video that shows how to build a UX portfolio with Notion. Most of the tips apply for a Service Design portfolio too.