Who are the scholars who stated that congregational prayer is a collective obligation (fard kifayah) or a confirmed Sunnah (sunnah mu'akkadah), and what are their proofs for that? Are there any contemporary scholars who hold this view?

Scholars have differed on the ruling concerning congregational prayer, holding various opinions:

Fard Kifayah (Communal Obligation): This is the most sound view according to the Shafi'is, and it is the opinion of the majority of their early scholars.

Sunnah Mu'akkadah (Emphasized Sunnah): This is the view of most Malikis.

Wajib 'Aynan (Individual Obligation): This is the preponderant view among the Hanafis, and it is the madhhab of the Hanbalis.

The position supported by evidence is that congregational prayer is an individual obligation (wajib 'aynan) upon adult men who are free from valid excuses.