Accessing open datasets of Landsat 8 via S3 bucket

After accessing Sentinel 2's (L2) open dataset I tried to retrieve Landsat 8 datasets via bucket- landsat-pds. However, the bucket is not available on the registry.opendata.aws. I still tried. It did not call any datasets.

I always prefer harmonized Sentinel 2 data but I wanted to find if L8 data could be retrieved. I was using this script to get L8 data (Note: I tried it using the old and obsolete without credentials method):

import os
import boto3
from botocore.handlers import disable_signing

s3 = boto3.resource('s3')
s3.meta.client.meta.events.register('choose-signer.s3.*', disable_signing)
bucket = 'landsat-pds' # L8 bucket = landsat-pds

s3bucket = s3.Bucket(bucket)

path = '173'
row = '052'

prefix = "c1/L8/{}/{}/".format(path, row)

for object_summary in s3bucket.objects.filter(Prefix=prefix):
    # to get the output in a full AWS path,
    vsis3_s3_img_path = os.path.join("/vsis3/", bucket, object_summary.key).replace("\\", "/")
    print(vsis3_s3_img_path)

1. Is the bucket landsat-pds available anymore or only usgs-landsat/collection02/`bucket for Landsat 8 datasets accessible?
2. Can the bucket usgs-landsat/collection02/ be accessed without credentials?
3. Element 84 used to handle the L8's open data collection but I could not trace a second L8 data source except the one managed by USGS.