The EU digital decade 2030 connectivity targets require parallel fixed Fiber and mobile 5G investments from Mobile Network Operators, however majority of data traffic generated and monetized by Big Techs (Hyperscalers), therefore operators require a fair share contribution. The aim of this paper to compare fair share contribution to virtual and cloud technology enabled cost efficient co-investment scenario between Operators and Big Techs in RAN and Core networks. The Research Question seeks to address the question of to what extant Operators and Big Techs public cloud co-investment meet the fair share financial contribution principle for 5G rollout. The Hypothesis tested is the fair share contribution principle requested by operators and already politicians to accelerate 5G deployment. The Research Methodology employed focusing on conclusive researches mainly with descriptive analysis based on secondary data. Qualitative analysis covers incumbent and rival MNOs’ financial incentives and conduct, as well as quantitative analysis applied on consultancies forecasted financial impact. The expected finding emerged from this study is the co-investment partnership with Big Techs into public cloud provides cost efficiency to Mobile Network Operators that is already a market driven first contribution to fair cost sharing of 5G investments. The originality of the paper to call attention for this connection, so fair share contribution has a prelude that parallel is widespread.