Shall we keep or drop custom breakpoints? Your vote counts

Problem/Motivation

I am happy to announce that Responsive image integration is almost 90% done with the latest work here:
#3097685: Support aspect ratio for Responsive image

The remaining 10% is to make the Responsive image work with Blazy CSS background.
This is still a question -- the only reason the custom breakpoint is still kept for now. Multi-breakpoint CSS backgrounds with Responsive image is still tough to cope with (due to picture + too many unpredictable breakpoints which Blazy script itself might not be able to deal with correctly, CMIIW). Yet was already done with custom breakpoints since likely early developments

On the other hand, the custom breakpoints do share at least 200 lines as seen at \Drupal\blazy\BlazyBreakpoint. Temporary solution was already provided as an option via Blazy UI to just disable these lines. Meaning you are being facilitated to a great extent, you can disable it if you don't use CSS background, nor custom breakpoints.

And now you are also being facilitated to drop it for good.

There are so many modules with CSS background images, but many are not multiple-breakpoint responsive nor lazyloaded -- another reason to keep Blazy CSS background feature around. I am shocked that I found so many just now:

1. https://www.drupal.org/project/bg_image_formatter
2. https://www.drupal.org/project/background
3. https://www.drupal.org/project/bg_image
4. https://www.drupal.org/project/bg_img_field
5. https://www.drupal.org/project/dynamic_background
6. https://www.drupal.org/project/background_image_formatter
7. https://www.drupal.org/project/field_group_background_image
8. https://www.drupal.org/project/background_image
9. https://www.drupal.org/project/responsive_background_image
10. https://www.drupal.org/project/image_background_formatter
11. https://www.drupal.org/project/simple_background_image_formatter
12. https://www.drupal.org/project/cs_adaptive_background_image
13. https://www.drupal.org/project/responsive_background
14. https://www.drupal.org/project/entity_background
15. https://www.drupal.org/project/simple_background
16. https://www.drupal.org/project/picture_background_formatter
17. https://www.drupal.org/project/bg_rotate
18. https://www.drupal.org/project/backgroundfield
19. https://www.drupal.org/project/headerimage
20. https://www.drupal.org/project/image_format_cover
21. https://www.drupal.org/project/backstretch
22. https://www.drupal.org/project/particle_responsive
23. https://www.drupal.org/project/parallax_bg
24. https://www.drupal.org/project/ckeditor_bgimage
25. https://www.drupal.org/project/image_base64_formatter

Proposed resolution

Second opinions are needed and very much appreciated:
Shall we keep or drop custom breakpoints?
If dropped, please suggest a solution based on the above problems. Perhaps joining forces with one of them, and drop Blazy?
If kept, why?

Please continue, ignore my absence, if you don't see me reply to your comment. I would try to refrain replying to avoid bias for now, and let it flow. You are given situations above, feel free to share your thoughts. I will again ask you before I decide anything after having enough representatives whatever it will be.

Thank you in advanced!

Remaining tasks

Not sure to deal with this, but perhaps a vote for keep or drop?
If so, please state your opinion with reasons, or even just +1 (keep) or -1 (drop).

User interface changes

Depends on the final decision.

API changes

(API changes/additions that would affect module, install profile, and theme developers, including examples of before/after code if appropriate.)

Data model changes

None.

Release notes snippet

None.