These strips allowed the insertion of both ICs and components.
They could be cut to any length and often could fit within each other.
Also at one time wire wrapping digital circuits was a common practice.
Trimming leads to the right length makes things more solid.
All other connections appear to be very solid.
This is somewhat dependent on soldering skill.
Making some end-caps does appear to improve things.
The longest lead as possible should be in its hole.
Every contact but the proto-board should be solid.
Perhaps some proto-boards use better sockets.