According to Jain tradition, the original 14 Pūrvas are completely lost as independent texts.

Very briefly, by tradition:

• Both Śvetāmbara and Digambara agree that:

- The 14 Pūrvas once formed the oldest and most comprehensive Jain scripture. - They were embedded in the 12th Aṅga called Dṛṣṭivāda. - Over time, the Pūrvas and then Dṛṣṭivāda itself disappeared from direct memory and manuscript form. ( jainbelief.com)

• Śvetāmbara view (summary)

- Already at the early councils, monks admitted that Dṛṣṭivāda (and thus the Pūrvas) were no longer fully preserved. - Only references, summaries, or echoes of their teachings survive in some Aṅga and ancillary texts (like Nandī and Samavāyāṅga). ( en.wikipedia.org)

• Digambara view (summary)

- They generally hold that all original Āgamas including the Pūrvas were lost very early (around first–second century CE). - However, certain later Digambara works (especially Ṣaṭkhaṇḍāgama and Kaṣāyapāhuḍa) are said to be based on fragments of Pūrva‑knowledge remembered by Ācārya Dharaśena and written down by his disciples. So, only indirect reflections, not the Pūrvas themselves, are considered to survive. ( prepp.in)

So, in simple terms:

• How much of the Pūrvas survive today?

- No Pūrva survives as a complete, original scripture. - What survives is: - Names and broad subject‑headings of the 14 Pūrvas. - Scattered quotations, summaries and doctrines in later Āgamas (Śvetāmbara) and in early Digambara texts (like Ṣaṭkhaṇḍāgama), which are said to be derived from or inspired by the Pūrvas. - Therefore, from a strict traditional standpoint: the Pūrvas themselves are lost; only their influence remains.

You can read a concise Jain-focused explanation here