If one assumes late 1980s as the peak of Soviet naval power, then one can say the following: Soviets surface navy, 1000-ish km away from their shores, was crazy powerful, with numerous naval aviation operating from the shores, many coastal antiship batteries, many attack boat and corvette sized ships.
But farther than that, their frigates and larger ships were not many fold more powerful than if they'd use today's PLAN numbers and types (with late 1980s tech). Roughly two times, I'd say. With the tendency that the gap narrows down as PLAN puts in service larger ships and more carriers.
Of course, they had more submarines, 108 conventional versus 40ish PLAN's, and 122 (non SSBN) versus 5+ for PLAN. Those alone would make a huge difference.
Their large surface combatants in 1989 were:
27 Krivak frigates 3k tons
26 Kashin/Kinda/Kanin frigates, 5k tons
36 Kresta/udaloy/sovremeny destroyers 7-8k tons
7 kara cruisers 10k
3 slava cruisers 12k
6 sverdlov cruisers 16k (1950s ships)
3 kirov cruisers 26k tons
4 kiev aviation cruisers 45k tons (carrying some Yak-38)
2 moskva helicopter cruisers 17k tons
that's 113 ocean going ships. total tonnage 975,000 tons.
versus PLAN's:
1 carrier 60-ish k tons
14 destroyers with 7+ k tons
5 destroyers with 5 k tons
4 destroyers with 8k tons
28 frigates with 4k tons
6 destroyers with 3.5 k tons
possibly counting 10 more 2.4k ton frigates. (soviets had a gap between 3000k and 1500k ships)
that's 68 ships with total tonnage of 375,000 tons
So numbers wise it was 60% and tonnage wise it was 38%. But the fact soviets did not operate any proper aircraft carriers is quite a game changer. Single Kuznetsov type carrier might be worth more than all four Kiev carriers with their poor Yak-38 planes, even if some notational very early su-33 with 1980s tech is used instead of J-15. Such planes would enable total control of the air and long range surveillance of the seas, whereas Soviets lacked an aerial platform with such range and such radars.
Still, the submarine difference alone might be deciding factor, if technology levels are the same as Soviets had in late 1980s.
But with every added carrier PLAN is getting more powerful. So by mid 2020s a navy with PLAN's numbers and tonnage and 1980s tech might actually hold its own against Soviet navy in the open seas.
Of course, with today's technology, even today's PLAN would possibly win over 1989 Soviet navy in the open ocean.