In Vedas , Aditi is the wife of Vishnu. That doesn't mean Lakshmi is not the wife of Vishnu .
As per Aditi suktam , In Rigveda she is the primordial god and mother of devatas .
- अदितिर्द्यौरदितिरन्तरिक्षम्
- अदितिर्माता स पिता स पुत्रः ।
- विश्वे देवा अदितिः पञ्च जना
- अदितिर्जातमदितिर्जनित्वम् ॥
- “Aditi is heaven; Aditi is mid-space;
- Aditi is mother, and she is father and son.
- Aditi is all the gods and the five peoples;
- Aditi is what has been born and what is yet to be born.”
Taittariya aranyaka clearly mentions her spouse which is Vishnu. Vedas don't have multiple Aditis. She is the same Aditi from rigveda with similar characteristics of power
- ध्रुवा दिशां विष्णुपत्न्यघोरा
- ऽस्येशाना सहसो या मनोता ।
- बृहस्पतिर् मातरिश्वोत वायुः
- संधुवाना वाता अभि नो गृणन्तु ॥
- विष्टम्भो दिवो धरुणः पृथिव्या
- अस्येशाना जगतो विष्णुपत्नी ।
- विश्वव्यचा इषयन्ती सुभूतिः
- शिवा नो अस्त्वदितिरुपस्थे ॥
- “Firm, of the directions, Viṣṇu's wife, unassailable, sovereign of strength, she who is intelligence/impulse…”
- “The support of heaven, the foundation of earth, sovereign of the world, Viṣṇu's wife; all-pervading, impelling, well-being—may Aditi be auspicious in our presence.”
As far as Lakshmi devi is concerned . She is praised in Lakshmi suktam as the wife of Vishnu. Lakshmi suktam is pretty much a part of vedic composition in ashvalayana samhita which is even quoted by Patanjali in 3BCE and it's considered much older than upanishads dating . So , neanderthals should not bring this stupid argument that laksmi suktam is not a part of Sri suktam. Sayanacharya literally includes Lakshmi suktam after Sri suktam verses.
- Āśvalāyana V.89
- Mahālakṣmī, the “Great Goddess Lakṣmī,” ... Lakṣmī as the wife of Viṣṇu.
So , vedas pretty much mention Lakshmi as the spouse of Vishnu. Vishnu is called yonder adithya in shatapatha brahmana and uttaranarayana anupama only refers to him.