If you use Ublock you can add this to your filters to restore a sane number of videos per row:

---

! YouTube 7 Videos Per Row Fix (Home and Channel Pages)

youtube.com##ytd-rich-grid-row:style(display:contents !important;)

youtube.com###contents.ytd-rich-grid-row:style(display:contents !important;)

youtube.com##ytd-rich-grid-renderer:style(--ytd-rich-grid-items-per-row: 7 !important;)

! YouTube 7 Videos Per Row Fix (Channel Page margin fix)

youtube.com##ytd-rich-item-renderer:style(margin-right: calc(var(--ytd-rich-grid-item-margin)/2) !important; margin-left: calc(var(--ytd-rich-grid-item-margin)/2) !important;)

! YouTube 7 Videos Per Row Fix (Font Size fix)

youtube.com###video-title.ytd-rich-grid-media:style(font-size: 1.4rem !important; line-height: 2rem !important;)

youtube.com###metadata-line.ytd-video-meta-block:style(font-size: 1.2rem !important; line-height: 1.8rem !important;)

youtube.com###video-title.ytd-rich-grid-slim-media:style(font-size: 1.4rem !important; line-height: 2rem !important;)