Early Buddhism unapologetically favoured homelessness / monasticism for those striving to Awaken. Relationships —not only with their web of obligations, incl. moral / ethical duties, but also with their entangled sources of peer-pressure toward the status quo— were seen as major distractions, hurdles, binds. The ‘renunciants’ very clearly renounce the ‘ordinary’ ways of life.
This is not to say that spiritual progress wasn't accessible to lay people though. Some lay followers are praised enough in some suttas for it to be ambiguous whether they've reached “the goal of holy life.” Such examples tend to be sought by modern “secular Buddhists”.
And even if one takes the monastic (self-serving) perspective that it's virtually (if not theoretically) impossible for lay people to fully Awaken, the orthodox Theravāda school makes it clear that it's possible:
the monastic code (Vinaya (Mahāvagga, first Khandaka —the admission to the Order of bhikkhus)) mentions Yasa as a lay person attaining enlightenment, who ordained shortly thereafter;
the commentaries mention a few others (Santati, Uggasena… but some always dispute what's not canonical per se);
the Milinda Pañha formalises this possibility by pretending that « if a layman attains arahantship, only two destinations await him: either he must enter the Order that very day or else he must attain parinibbàna » (other places suggest « within 7 days » rather than « that very day »). Of course, the answers on these points come from bhikkhu Nagasena, not the Buddha himself, and are therefore subject to contestation;
the existence of paccekabuddhas (“solitary buddhas”; ‘solitary’ as in isolated from Dhamma and sangha, they're not necessarily hermit… … … …