Well, I didn't watch the video. For whatever reason, Rick Beato tends to annoy me.
Joni Mitchell rows her own boat and stands tall on her own mountain, she can do whatever she wants.
When I played in a Motown cover band there were lots of dance floor fillers and quite a few sing-a-longs. Everybody sang "How sweet it is to be loved by you" everytime. Simple but a great hook.
If you feel like all the ideas are used up, listen to some Ray Stevens, maybe give Nillson's Lime In The Coconut a spin.
Try The Who "I'm a Boy" or the Kinks "Sunny Afternoon".
Read Kafka's Metamorphosis, where the hell did that come from? https://www.kafka-online.info/the-metamorphosis.html
A song can just be fun, it can have multiple meanings - some of these can only be understood by the writer sometimes.
Fear of stupidity is in itself stupid. If you go stupid, go really stupid and have fun. Be a kid, the precedent is well established.
Sometimes I think our intention to excell kills our creativity. Spew forth and pluck the nuggets from the ensuing mess. I used to "edit" when I wrote, now I just let whatever is in my head come out.
I am not saying that everything I write now is brilliant, not by any means. I am saying that I am finding it much more fun and much easier to just allow the creativity to flow when it flows and figure out what to do with it later.