Terumah starts a series of chapters that describe the construction of the Tabernacle in great detail. We know that both in Egypt and Mesopotamia temples and palaces were the core of any city and society. It was a matter of national pride to describe them in intricate detail. The more intricate the more authority and power they projected. These structures had to be finer and richer than any other.
It was natural therefore that the Israelites would want to build only the best they could for God. It had to be portable given their circumstances. But it would be a template for the Temple when, eventually they settled down in their own country. And like any important gift. One would want to emphasize all the valuable elements that were used as well as the intricacies of construction.
But there is an issue here. Surely God is everywhere. And we all have access to God. Why would we need to have a Tabernacle altogether? A Tent of Assembly might make sense as the center for Government and Law. But why a Temple?
There is a debate amongst the commentators as to whether the Tabernacle was designed on Sinai and a priori as a requirement. Or whether it was only after the Golden Calf episode that it was decided that the people needed somewhere physical to remind them of their relationship with God. The mechanisms of worship were dictated by the circumstances, the time and need to help people transition from a God in appearance and physical symbolism into one of no physicality altogether.
It might also be because God was present amongst them in the community togetherness as well as the individual experience. The Tabernacle reminded them of God in community.
Rather like today the role of synagogue is communal rather than for individual spirituality which needs no boundaries or forms. We need both.