30fps versions are still there on the server, its the default player hiding them from you. There is even 4K 30fps file available 313.

D:\_learning>youtube-dl.exe -F https://www.youtube.com/watch?v=LXb3EKWsInQ
[youtube] LXb3EKWsInQ: Downloading webpage
[info] Available formats for LXb3EKWsInQ:
format code extension resolution note
249 webm audio only tiny 57k , opus @ 50k (48000Hz), 1.89MiB
250 webm audio only tiny 75k , opus @ 70k (48000Hz), 2.53MiB
140 m4a audio only tiny 130k , m4a_dash container, mp4a.40.2@128k (44100Hz), 4.84MiB
251 webm audio only tiny 148k , opus @160k (48000Hz), 4.96MiB
394 mp4 256x144 144p HDR 88k , av01.0.00M.10.0.110.09.16.09.0, 30fps, video only, 2.34MiB
278 webm 256x144 144p 97k , webm container, vp9, 30fps, video only, 3.38MiB
160 mp4 256x144 144p 111k , avc1.4d400c, 30fps, video only, 2.87MiB
395 mp4 426x240 240p HDR 191k , av01.0.00M.10.0.110.09.16.09.0, 30fps, video only, 4.33MiB
242 webm 426x240 240p 233k , vp9, 30fps, video only, 6.89MiB
330 webm 256x144 144p60 HDR 243k , vp9.2, 60fps, video only, 7.96MiB
133 mp4 426x240 240p 245k , avc1.4d4015, 30fps, video only, 5.86MiB
396 mp4 640x360 360p HDR 403k , av01.0.01M.10.0.110.09.16.09.0, 30fps, video only, 8.67MiB
243 webm 640x360 360p 435k , vp9, 30fps, video only, 12.85MiB
331 webm 426x240 240p60 HDR 504k , vp9.2, 60fps, video only, 16.65MiB
134 mp4 640x360 360p 633k , avc1.4d401e, 30fps, video only, 15.49MiB
397 mp4 854x480 480p HDR 735k , av01.0.04M.10.0.110.09.16.09.0, 30fps, video only, 15.80MiB
244 webm 854x480 480p 857k , vp9, 30fps, video only, 23.18MiB
332 webm 640x360 360p60 HDR 1059k , vp9.2, 60fps, video only, 35.72MiB
135 mp4 854x480 480p 1496k , avc1.4d401f, 30fps, video only, 30.03MiB
398 mp4 1280x720 720p60 HDR 1552k , av01.0.08M.10.0.110.09.16.09.0, 60fps, video only, 35.98MiB
247 webm 1280x720 720p 1697k , vp9, 30fps, video only, 46.97MiB
333 webm 854x480 480p60 HDR 1988k , vp9.2, 60fps, video only, 69.11MiB
399 mp4 1920x1080 1080p60 HDR 2683k , av01.0.09M.10.0.110.09.16.09.0, 60fps, video only, 65.43MiB
302 webm 1280x720 720p60 2742k , vp9, 60fps, video only, 76.27MiB
136 mp4 1280x720 720p 3220k , avc1.4d401f, 30fps, video only, 57.62MiB
248 webm 1920x1080 1080p 3249k , vp9, 30fps, video only, 84.22MiB
298 mp4 1280x720 720p60 3483k , avc1.4d4020, 60fps, video only, 92.61MiB
137 mp4 1920x1080 1080p 4337k , avc1.640028, 30fps, video only, 103.11MiB
334 webm 1280x720 720p60 HDR 4524k , vp9.2, 60fps, video only, 162.28MiB
303 webm 1920x1080 1080p60 5018k , vp9, 60fps, video only, 134.10MiB
299 mp4 1920x1080 1080p60 5794k , avc1.64002a, 60fps, video only, 163.70MiB
335 webm 1920x1080 1080p60 HDR 6920k , vp9.2, 60fps, video only, 252.07MiB
400 mp4 2560x1440 1440p60 HDR 8626k , av01.0.12M.10.0.110.09.16.09.0, 60fps, video only, 223.85MiB
271 webm 2560x1440 1440p 9621k , vp9, 30fps, video only, 249.96MiB
308 webm 2560x1440 1440p60 13357k , vp9, 60fps, video only, 388.12MiB
336 webm 2560x1440 1440p60 HDR 16917k , vp9.2, 60fps, video only, 607.18MiB
401 mp4 3840x2160 2160p60 HDR 18167k , av01.0.13M.10.0.110.09.16.09.0, 60fps, video only, 460.07MiB
313 webm 3840x2160 2160p 18852k , vp9, 30fps, video only, 628.46MiB
315 webm 3840x2160 2160p60 26568k , vp9, 60fps, video only, 956.39MiB
337 webm 3840x2160 2160p60 HDR 30646k , vp9.2, 60fps, video only, 1.05GiB
18 mp4 640x360 360p 655k , avc1.42001E, 30fps, mp4a.40.2@ 96k (44100Hz), 24.53MiB
22 mp4 1280x720 720p 1669k , avc1.64001F, 30fps, mp4a.40.2@192k (44100Hz) (best)