The 3-2-1 backup rule

What is your strategy? I would love to hear your opinion on this.

For me, I store my backups (4 active laptops) on 3 external drives (2 SSDs and 1 Hard Drive). No Nas or cloud storage for me.
For each laptop, I create 2 backups, all verified (one using MR and the other using a non-MR backup software).

I'm a Microsoft 365 subscriber which includes 1 Terabyte of OneDrive cloud storage. I work entirely from my local 1 Terabyte C: Drive and all my data and photos are kept in my local OneDrive folder. I have cloud OneDrive set to mirror my local OneDrive folder; thus I always have all my work backed up throughout the day in real-time as I work. This is vitally important to me as I don't ever want to lose even a single byte of anything I'm currently working on.

I make a Macrium Reflect image every night before shutting down, alternating between two 4TB Samsung T9 Portable SSD's, each containing 15 rotating daily images. This results in always having a full image of my C: drive and all my data going back every day for 30 days.

I adhere to the 3-2-1 backup strategy. I always have 3 copies of my data on 2 different media types with 1 copy kept offsite in continuous real-time.