Here is the screenshot showing memory consumption of Obsidian (I did wait 30 seconds for memory to settle down after initial spike which was 240 MB): https://pasteboard.co/uW2lPNSbL7f7.png
Obsidian is an Electron app (I don't know if it belongs to the Block editor category). It loads just as fast as your app. I tried copying and pasting the text file War and Peace (66035 lines) from Notepad into both apps and, interestingly, Obsidian is slightly faster. Also, scrolling through this large chunk of text is slightly faster on Obsidian, too. Obsidian memory consumption (4 processes) is 172 MB and Daino Notes consumption (1 process) is 352.7 MB. Tested on Windows 11 PC.
[EDIT] Here is memory consumption of Daino Notes: https://pasteboard.co/z5pciLoh99i6.png